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1. gt T elsa Secondary Functions emperature p gt SET EXIT M a Y 4 e EXIT Display Power I I 4 EXIT Reset Cutout l SET A SET i Cutout Active ES EXIT Set Proportional Band AA P I Y SET EXIT Select Setpoint SET EXIT Set Cutout Temp y SET MC EXIT Adjust Setpoint I SET Y EXIT Adjust Vernier EXIT I SET Y EXIT Set Scale C F Configuration Menu 4 SET SET i EXIT EXIT EXIT E EXIT EXIT gt Operating Serial up IEEE 488 ye on psu 4 DOWN Parameters Interface DOWN Interface pown Eann on le PM Menu 1 Menu lt ro c 1
2. 11 11 1 11 2 Calibration Procedure A Note This procedure is to be considered a general guideline Each labo ratory should write their own procedure based on their equipment and their quality program Each procedure should be accompanied by an un certainty analysis also based on the laboratory s equipment and environ ment In some instances the user may want to calibrate the bath to improve the tem perature set point accuracy Calibration is done by adjusting the controller probe calibration constants DO and DG so that the temperature of the bath as measured with a standard thermometer agrees more closely with the bath set point The thermometer used must be able to measure the bath fluid temper ature with higher accuracy than the desired accuracy of the bath By using a good thermometer and carefully following the procedure the bath can be cali brated to an accuracy of better than 0 1 C over a range of 50 degrees Calibration Points In calibrating the bath DO and DG are adjusted to minimize the set point error at each of two different bath temperatures Any two reasonably separated bath temperatures may be used for the calibration however best results are obtained when using bath temperatures which are just within the most useful operating range of the bath The farther apart the calibration temperatures the larger will be the calibrated temperature range but the calibration error will also be greater over the range If
3. Figure 5 Drain Location and Lid Options 25 7012 Calibration Bath User s Guide 26 4 5 6 The stirrer pump motor drives the stirring propellers to provide mixing of the bath fluid Proper mixing of the fluid is important for good con stant temperature stability and uniformity The stir motor power cord plugs into the back of the bath at the power socket labeled STIRRER The probe hole is for the temperature controller probe The probe must be in this hole for the bath to operate A drain valve is provided for ease of removing the fluid media from the bath Always use a container of adequate size to hold the full load of fluid Some oils are more easily drained at higher temperatures See caution note below WARNING Extreme caution must be maintained to prevent harm to the user or the surrounding environment Do not exceed a 120 C fluid temper ature for draining The valve could be damaged if 120 C is exceeded Insulate the container from the floor or other objects that may be damaged by high temperatures as required 8 General Operation Heat Transfer Fluid 8 1 8 1 1 8 1 2 General Operation Heat Transfer Fluid Many fluids will work with 7012 bath Choosing a fluid requires consideration of many important characteristics of the fluid Among these are temperature range viscosity specific heat thermal conductivity thermal expansion electri cal resistivity fluid lifetime safety a
4. Hart Scientific 9 7012 Calibration Bath User Manual Rev 992802 Rev 992802 Limited Warranty amp Limitation of Liability Each product from Fluke Corporation Hart Scientific Division Hart is warranted to be free from de fects in material and workmanship under normal use and service The warranty period is one year for the Calibration Bath The warranty period begins on the date of the shipment Parts product repairs and ser vices are warranted for 90 days The warranty extends only to the original buyer or end user customer of a Hart authorized reseller and does not apply to fuses disposable batteries or to any other product which in Hart s opinion has been misused altered neglected or damaged by accident or abnormal conditions of operation or handling Hart warrants that software will operate substantially in accordance with its functional specifications for 90 days and that it has been properly recorded on non defective media Hart does not warrant that software will be error free or operate without interruption Hart does not warrant calibrations on the Calibration Bath Hart authorized resellers shall extend this warranty on new and unused products to end user customers only but have no authority to extend a greater or different warranty on behalf of Hart Warranty support is available if product is purchased through a Hart authorized sales outlet or Buyer has paid the applicable international price Hart reserves t
5. The digital LED display on the front panel allows direct viewing of the actual bath temperature This temperature value is what is normally shown on the dis play The units C or F of the temperature value are displayed at the right For example Bath temperature in degrees Celsius The temperature display function may be accessed from any other function by pressing the EXIT button Reset Cutout If the over temperature cutout has been triggered then the temperature display will alternately flash Cutb out i Indicates cutout condition The message continues to flash until the temperature is reduced and the cutout is reset The cutout has two modes automatic reset and manual reset The mode de termines how the cutout is reset which allows the bath to heat up again When in automatic mode the cutout resets itself as soon as the temperature is lowered below the cutout set point With manual reset mode the cutout must be reset by the operator after the temperature falls below the set point When the cutout is active and the cutout mode is set to manual reset then the display will flash c vt out until the user resets the cutout To access the reset cutout function press the SET button SET Access cutout reset function The display will indicate the reset function 37 7012 Calibration Bath User s Guide
6. cessively from the set point due to varying external conditions This is because the power output changes very little with temperature and the controller cannot respond very well to changing conditions or noise in the system If the propor 9 Controller Operation Proportional Band tional band is too narrow the bath temperature may swing back and forth be cause the controller overreacts to temperature variations For best control stability the proportional band must be set for the optimum width MAMAN A Proportional Band too Narrow Proportional Band too Wide Optimum Proportional Band Da Figure 8 Bath temperature fluctuation at various proportional band settings The optimum proportional band width depends on several factors among which are fluid volume fluid characteristics viscosity specific heat thermal conduc tivity heater power setting operating temperature and stirring Thus the pro portional band width may require adjustment for best bath stability when any of these conditions change Of these the most significant factors affecting the op timum proportional band width are heater power setting and fluid viscosity The proportional band should be wider when the higher power setting is used so that the change in output power per change in temperature remains the same Table 3 Proportional Band Fluid Table Proportional Fluid Temperature Heater Setting Band Stability Water 30 0 C Low 0 04 C 0 0004 C W
7. Normally the cutout disconnects power to the heater when the bath temperature exceeds the cutout set point causing the temperature to drop back down to a safe value If the cutout mode is set to AUTO the heater switches back on when the temperature drops If the mode is set to RESET the heater only comes on again when the temperature is reduced and the cutout is man ually reset by the operator see Section 9 8 Cutout Check that the cutout set point is adjusted to 10 or 20 C above the maximum bath operating temperature and that the cutout mode is set as desired e f the cutout activates when the bath temperature is well below the cutout set point or the cutout does not reset when the bath temperature drops and it is manually re Set then the cutout circuitry or the cutout thermocouple sensor may be faulty or disconnected Contact an Autho rized Service Center see Section 1 3 on page 5 for as sistance 67 7012 Calibration Bath User s Guide 68 Problem Causes and Solutions The display flashes cutout and an incorrect process temperature The problem may be that the controller s voltmeter circuit is not func tioning properly A problem could exist with the memory back up battery If the battery voltage is insufficient to maintain the mem ory data may become scrambled causing problems A nearby large static discharge may also affect data in memory Verify that the parameters on the Report of Te
8. Serial Communications The bath may be installed with an RS 232 serial interface that allows serial digital communications RS 232 Cable Wiring for over fairly long distances With IBM PC and Compatibles the serial interface the user may access any of the functions pa rameters and settings discussed in Instrument Computer DTE ith th f Connector Connector Section 9 with the exception o DB 9 Pin DB 9 Pin the BAUD rate setting The serial 1NC m 1DcD interface uses 8 data bits 1 stop 2RxD E 2RD 3TxD 3TxD bit and no parity rae t m 5 GND 5 GND el 6NC 6 DSR Wiring 7RTS 7RTS 8CTS 8CTS The serial communications cable 9NC 9NC attaches to the bath through the DB 9 connector at the back of the instrument Figure 9 shows the Instrument Computer DTE pin out of this connector and sug connector Connector gested cable wiring To eliminate DB 9 Pin DB 25 Pin noise the serial cable should be INC shielded with low resistance be mis M d tween the connector DB 9 and 4NC e 4 RTS the shield 5 GNDe 5CTS 6NC Sk 6DSR 7RTS SL reno Setu p 8CTS 8DCD 9NC 20DTR Before operation the serial inter face of the bath must first be set Figure 9 Serial Communications Cable Wiring 51 7012 Calibration Bath User s Guide 52 10 1 2 1 10 1 2 2 10 1 2 3 10 1 2 4 up by programming the baud rate and other configuration parameters Thes
9. 32 14 5 5 41 20 7 10 50 27 9 15 59 36 1 20 68 45 5 25 77 56 2 30 86 68 4 35 95 82 1 37 98 6 86 DO NOT set the Cooling Pressure above 90 PSIG 3 The cooling temp gauge is used to indicate the temperature at which the refrigerant is evaporating The cooling temp regulating valve is used to set and then control this temperature Back Panel The back panel has five standard features and two optional features see Figure 4 1 the probe connector 2 the stirrer power outlet 3 the power cord 4 the drain valve 5 serial number notation 6 the RS 232 interface connecter op tional and 7 the IEEE 488 interface connector optional The system fuses are internal 1 The probe connector on the back panel is used for the temperature con troller probe 2 The stirrer power is provided for the stirring motor 3 The power cord 4 A drain valve is provided for ease of removing the fluid media from the bath Always use a container of adequate size to hold the FULL LOAD of fluid Some oils are more easily drained at higher temperatures See caution note in next section 23 7012 Calibration Bath User s Guide O E JE 2 RS 232 QU ABEL LE LEUTE Figure 4 Back Panel Sd 5 The serial number is located on the upper right corner of the back panel When contacting an Authorized Service Center use the serial number and model number 6 If the bath is su
10. 9 4 Temperature Scale Units 41 9 5 secondary MENU 8 Sak ds ele eo Be Bu WES SS 42 9 6 Heater POWER s soe eges he hom Red a we Se 42 9 7 Proportional Band 42 9 8 Cutout Lo zoo AA 44 9 9 Controller Configuration 45 9 10 Probe Parameters gt sso tmr RS 46 9 10 1 Doc 46 0302 De xc mcns a LN EE 46 9 1 Operating Parameters 46 9 11 1 Cutout Reset Mode vs iu oue dl Re A ad da n 46 9 12 Serial Interface Parameters 47 9 12 1 Baud co c seo aa abr e 47 9 12 2 Sample Period saaa duce pad OR ger eue E Beds ve S oe A 48 9 12 3 Duplex Mode 42s tege EORR Wr cae el gical M gti ld I OW E 48 9 12 4 Tanefeediz sali ead un vr nie de Bot ate vay dedo e atout ud 48 0 15 IEEB 488 Parameters o e coco a veut 49 9 13 1 IEBE 488 Address 49 9 14 Calibration Parameters 49 9 14 1 CTOS und A NN 50 9 14 2 jupe C CIC a a iia eee 50 10 Digital Communication Interface 51 10 1 Serial Communications 51 10 1 1 WIDE voco soed e mto e ORA moin A HO OD QS Re de qed 51 10 1 2 Setup esa UR OR a e UR E e RR den AR 51 10 121 Baud Tate es ida ede ee a pe a as aa Y 25 52 10 1 2 2 Sample Period i ore ROC o eU Eee ct See aa ge eo 52 10 1 2 3 gt Duplex Mode ne S eque dear PG ee DA qe ed ae As 52 10 1 2 4 Tanefeed 4 2 2 3 2 43 uo
11. C FL 302 C pe E FL 280 C pee i FL 232 C FL 211 C FL 133 C FL177 C BP mes FL 16 C BP FL 60 C Legend GE O Decomposition Starts Shaded area represents usable range of fluid starting at BP Boiling Point 50 centistokes Lighter shading represents decreasing CS Centistokes viscosity while vaporization and decomposition increase EP Evaporation Point Black area represents liquid range with excessive viscosity fluid loss due to evaporation FL Flash Point FR Freeze Point PP Pour Point Range over which a fume hood is recommended Figure 6 Chart of various bath fluids and their properties 8 1 11 2 About the Graph The fluid graph visually illustrates some of the important qualities of the fluids shown Temperature Range The temperature scale is shown in degrees Celsius A sense of the fluid s general range of application is indicated Qualities including pour point freeze point important viscosity points flash point boiling point and others may be shown 31 7012 Calibration Bath User s Guide Table 2 Table of various bath fluids and their properties Fluid Lower Upper Specific Heat Thermal Thermal Hart Part Temperature Temperature Flash Viscosity Specific cal g C Conductivity Expansi
12. equipment Fires and severe burns may result if personnel fail to observe safety precautions ELECTRICAL HAZARD e These guidelines must be followed to ensure that the safety mechanisms in this instrument will operate properly This mains supply for the instru ment must be capable of supplying power to the instrument as listed in Section 3 1 Specifications The power cord of the instrument is equipped with a three pronged grounding plug for your protection against electrical shock hazards It must be plugged directly into a properly grounded three prong receptacle The receptacle must be installed in accordance with local codes and ordinances Consult a qualified electrician DO NOT use an extension cord or adapter plug e DO use a ground fault interrupt device This unit contains a liquid A ground fault device is advised in case liquid is present in the electrical system and could cause an electrical shock e Always replace the power cord with an approved cord of the correct rat ing and type If you have questions contact an Authorized Service Center see Section 1 3 e High voltage is used in the operation of this equipment Severe injury or death may result if personnel fail to observe the safety precautions Before working inside the equipment turn off the power and disconnect the power cord BATH FLUIDS e Fluids used in this unit may produce noxious or toxic fumes under certain circumstances Consult the fluid manufacturer s M
13. heat up again If the mode is set to manual the heater remains disabled until the user manually resets the cutout The cutout set point may be accessed within the secondary menu Press SET and EXIT to enter the secondary menu and show the heater power Then press SET twice to access the cutout set point ex Access heater power in secondary menu le Pet 3 Heater power in percent To accept the new cutout set point press SET SET Accept cutout set point The next function is the configuration menu Press EXIT to resume display ing the bath temperature Controller Configuration The controller has a number of configuration and operating options and calibra tion parameters which are programmable via the front panel These are ac cessed from the secondary menu after the cutout set point function by pressing 45 7012 Calibration Bath User s Guide 46 9 10 9 10 1 9 10 2 9 11 9 11 1 SET There are 5 sets of configuration parameters probe parameters oper ating parameters serial interface parameters IEEE 488 interface parameters and controller calibration parameters The menus are selected using the UP and DOWN keys and then pressing SET Probe Parameters The probe parameter menu is indicated by PrObE Probe parameters menu Press SET to enter the menu The probe parameters menu contains the pa rameters DO and Dg which characterize the resist
14. or HALF Set serial duplex mode to full du plex f ull du f Set serial duplex mode to half du plex h alf du h Set serial linefeed mode Iffeed on of f ON or OFF Set serial linefeed mode to on Iffeed on If on Set serial linefeed mode to off If eed of f Ifzof Calibration Menu Read low set point limit value tllow tl tl 999 tl 80 Set low set point limit to n tllow n tl 80 999 9 to 999 9 Read high set point limit value th igh th th 999 th 205 Set high set point limit to n th igh n th 205 999 9 to 999 9 Miscellaneous not on menus Read firmware version number ver sion ver ver 9999 9 99 ver 2100 3 56 Read structure of all commands h elp h list of commands Read Heater f f f1 9 f1 1 Set Heater f1 1 0 0ori Set heater to low fl n f1 0 Set heater to high fl n f1 1 Read Refrigeration f2 f2 2 9 2 0 Set Refrigeration f2 1 0 0or1 Set Refrigeration to on f2 n f2 1 Set Refrigeration to off f2 n f2 0 Read Expansion Valve 1 f3 f3 f3 9 13 1 Set Expansion Valve 1 f3 1 0 Dor1 Set Expansion Valve 1 to on f3 n f3 1 Set Expansion Valve 1 to off f3 n 13 0 Read Cooling Power f4 f4 f4 9 14 1 Set Back Pressure f4 1 0 0 or 1 Set back pressure on f4 n f4 1 Set back pressure off f4 n f4 0 Legend Note Optional Command data Returns either information n Numeric data supplied by user 9 Numeric data returned to user X Character data returned to user When DUPLEX is set to FULL and a command is sent to READ t
15. sensor If damaged the probe can be replaced Con tact an Authorized Service Center for assistance Insert the probe into the 1 4 inch probe hole at the top left side of the bath lid The tip of the probe must be well immersed in the fluid The probe connector is plugged into the rear of the bath into the socket labeled PROBE Power With the bath power switch off plug the bath into an AC mains outlet of the appropriate voltage frequency and current capacity Refer to Section 3 1 Specifications for power requirement details Refer to and read the WARNING at the front of this manual concerning brownout and over voltage protection Be sure the stirring motor power cord is plugged into the STIRRER socket at the back of the bath 6 Bath Use General 6 1 6 2 Bath Use READ BEFORE PLACING THE BATH IN SERVICE The information in this section is for general information only It is not de signed to be the basis for calibration laboratory procedures Each laboratory will need to write their own specific procedures General Be sure to select the correct fluid for the temperature range of the calibration Bath fluids should be selected to operate safely with adequate thermal proper ties to meet the application requirements Also be aware that some fluids ex pand and could overflow the bath if not watched Refer to General Operation section 8 for information specific to fluid selection and to the MSDS sheet spe c
16. very low viscosity and good thermal conductivity and heat capacity which makes it among the best fluids for control stability at low temperatures Temperature stability is much poorer at higher temperatures because water condenses on the lid cools and drips into the bath Water is safe and relatively inert The electrical conductivity of water may pre vent its use in some applications Water has a limited temperature range from a few degrees above 0 C to a few degrees below 100 C At higher temperatures evaporation becomes significant Water used in the bath should be distilled or softened to prevent mineral deposits Consider using an algicide chemical in the water to prevent contamination Ethylene Glycol The temperature range of water may be extended by using a solution of 1 part water and 1 part ethylene glycol antifreeze The characteristics of the ethylene glycol water solution are similar to water Use caution with ethylene glycol since the fluid is very toxic Ethylene glycol must be disposed of properly Methanol Methanol or methyl alchohol is often used at low temperatures below 0 C Methanol is relatively inexpensive has good control characteristics and has a 29 7012 Calibration Bath User s Guide 30 8 1 10 4 8 1 10 5 8 1 11 8 1 11 1 low freeze point Methanol is very toxic so care must be taken when using and disposing of this fluid Mineral Oil Mineral oil or paraffin oil is often used at moder
17. C 0 00035 25 C 0 00075 100 25 C 5016 300 C fl oc 10 104 C 0 386 100 C 1 150 C 0 433 200 C Dow Corning 710 80 C v 302 C fl oc 302 C 50 80 C 1 11 25 C 0 363 40 C 0 00035 25 C 0 00077 100 25 C 7 204 C 0 454 100 C 1 150 C 5017 0 505 200 C Dow Corning 66 C v 315 C fl oc 315 C 50 66 C 0 96 25 C 0 34 100 C 0 0003 0 00095 100 25 C 210 H 14 204 C 10 150 C Silicone Oil Heat Transfer 145 C fr 530 C NONE 34 150 C 2 0 150 C 0 33 0 0014 0 00041 1 7 Q fcm Salt 6 5 300 C 1 9 300 C 5001 2 4 500 C 1 7 500 C Limiting Factors b boiling point e high evaporation fl flash point fr freeze point v viscosity Flash point test Very low water solubility ice will form as a slush from condensation below freezing oc open cup cc closed cup 32 Freezing Point The freezing point of a fluid is an obvious limitation to stir ring As the freezing point is approached high viscosity may also limit good stirring Pour Point This represents a handling limit for the fluid Viscosity Points shown are at 50 and 10 centistokes Greater than 50 centi stokes stirring is very poor and unsatisfactory for bath applications At 10 centistokes and below optimum stirring can occur These are rules of thumb which have been useful for most applications 8 General Operation Stirring 8 2 8 3 8 4 Fume Point The point at which a fume hood
18. IEEE 488 interface to read or set the tem perature or access other controller functions All commands are ASCII charac ter strings and are terminated with a carriage return CR ASCII 13 Interface commands are listed below Interface Commands The various commands for accessing the bath controller functions via the digi tal interfaces are listed in this section see Table 4 These commands are used with both the RS 232 serial interface and the IEEE 488 GPIB interface In ei ther case the commands are terminated with a carriage return character The in terface makes no distinction between upper and lower case letters hence either 53 7012 Calibration Bath User s Guide Table4 Interface Command Summary Command Command Returned Acceptable Command Description Format Example Returned Example Values Display Temperature Read current set point s etpoint S set 9999 99 C or F set 105 00 C Set current set point to n s etpoint n s 100 Instrument Range Read vernier v ernier V v 9 99999 v 0 00000 Set vernier to n v ernier n v 00001 Depends on Configuration Read temperature t emperature t t 9999 99 C or F t 55 69 C Read temperature units u nits u u x uc Set temperature units u nits c f CorF Set temperature units to Celsius _u nits c u C Set temperature units to u nits f u f Fahrenheit Secondary Menu Re
19. Lifetime e hs e dan MN we He SS Re reip rid 28 8 1 8 Sale aug o do vote wie de qos dot de bo TN Rides 28 8 1 9 COSE SR as Beck ve rene D nn ee dan dons 29 8 1 10 Commonly Used Fluids is e uou Exec ROO ede Rm S 29 SL TO Waters cu umo ROO Sx Rus a Rum dr RO RA ewe dc A AR 29 8 1 10 2 Ethylen Glycol s 000 ok nm RR ome songe RO UR que ey ds pais 29 8 1 10 3 Methanol ss a Up y RR UR RUE EES ER a a RUE ee EIE 29 SLIOS Mineral OIL oia exped ee dto dde ex Xd endi fe Re ut 30 8 1 10 5 Silicone Oils 2 3 ae is den yum Rok b RO RA Row RUN Ra OS AUR A 30 8 1 11 Fluid Characteristics Charts 30 8 1 11 1 Limitations and Disclaimer 30 SLIL Aboutthe Graph amp 43 x boo RO a tue Eos REOR SUR ADR AL de 31 8 2 SUMING m 33 8 3 POWER aTe ea DIM NN PAR RES De RU a Gs 33 8 4 Heater iia Bae ae a Nam peer RS 39 8 5 Coolmng s ieee ba ee a XC yep ego 34 8 6 Bluid Drain cas d scm a al Xr dae E 34 8 7 Temperature Controller 34 9 Controller Operation 37 9 1 Bath Temperature 37 9 2 Reset Cutouts s s m esos DURS qu ae a deo Ro Rod 37 9 3 Temperature Set point 39 9 3 1 ProgrammableSet points 39 9 3 2 Setpoint Valle solis 2 eue xe x RU Ou Ao e EURO ORO OR ERR 40 9 3 3 Setpoint Vernier d s see ed X eo Sor ex de e M X de ao Na e pos 40
20. OR CONSE QUENTIAL DAMAGES OR LOSSES INCLUDING LOSS OF DATA WHETHER ARISING FROM BREACH OF WARRANTY OR BASED ON CONTRACT TORT RELIANCE OR ANY OTHER THEORY Since some countries or states do not allow limitation of the term of an implied warranty or exclusion or limitation of incidental or consequential damages the limitations and exclusions of this warranty may not apply to every buyer If any provision of this Warranty is held invalid or unenforceable by a court of com petent jurisdiction such holding will not affect the validity or enforceability of any other provision Fluke Corporation Hart Scientific Division 799 E Utah Valley Drive e American Fork UT 84003 9775 USA Phone 1 801 763 1600 Telefax 1 801 763 1010 E mail support hartscientific com www hartscientific com Subject to change without notice Copyright O 2006 Printed in USA Table of Contents 1 Before YouStart 1 1 1 symbols Used uuo sure eG PUR tes 1 1 2 Safety Information 2 1 2 1 WARNINGS c e race acea dd ed A xo ea See ey x 2 1 2 2 CAUTIONS 5 2 de Seed tmo gr ce A avan UR C Ca re ins or n 4 1 3 Authorized Service Centers 5 2 Introduction 9 3 Specifications and Environmental Conditions 11 3 1 Specifications Le ae bon eo d une Eos REOR 11 3 2 Environmental Conditions 12 4 Quick St
21. SDS Material Safety Data Sheet Proper ventilation and safety precautions must be observed 7012 Calibration Bath User s Guide The instrument is equipped with a soft cutout user settable firmware and a hard cutout set at the factory Check the flash point boiling point or other fluid characteristic applicable to the circumstances of the unit opera tion Ensure that the soft cutout is adjusted to the fluid characteristics of the application As a guideline the soft cutout should be set 10 C to 15 C below the flash point of the bath fluid See Section 8 1 Heat Transfer Fluid for specific information on bath fluids and Section 9 8 Cutout 1 2 2 CAUTIONS To avoid possible damage to the instrument follow these guidelines Always operate the instrument in room temperatures listed in Section 3 2 Environmental Conditions Allow sufficient air circulation by leaving at least 15 cm 6 inches of clearance around the instrument DO NOT overfill the bath Overflowing liquid may damage the electrical system Be sure to allow for thermal expansion of the fluid as the bath temperature increases See Section 5 3 Bath Preparation and Filling for specific instructions Read Section 6 Bath Use before placing the unit into service DO NOT change the values of the bath calibration constants from the fac tory set values The correct setting of these parameters is important to the safety and proper operation of the unit The refr
22. The temperature range of the particular fluid used in the bath must be known by the operator and the bath should only be op erated well below the upper temperature limit of the liquid In addition the cutout temperature should also be set below the upper limit of the fluid Setting the bath temperature involves three steps 1 select the set point mem ory 2 adjust the set point value and 3 adjust the vernier if desired Programmable Set points The controller stores 8 set point temperatures in memory The set points can be quickly recalled to conveniently set the bath to a previously programmed tem perature set point To set the bath temperature one must first select the set point memory This function is accessed from the temperature display function by pressing SET The number of the set point memory currently being used is shown at the left on the display followed by the current set point value 25 00 Bath temperature in degrees Celsius Press SET to accept the new selection and access the set point value 39 7012 Calibration Bath User s Guide 40 9 3 2 9 3 3 SET Accept selected set point memory Set point Value The set point value may be adjusted after selecting the set point memory and pressing SET The set point value is displayed with the units C or F at the left t 468 00 Set point 4 value in C If the set point value need not be changed then press EXIT to resume dis pl
23. This bath is not designed to be portable Therefore moving the bath once it has been installed should be kept to a minimum CAUTION Never move a bath that is full of fluid This action could be extremely dangerous and could result in personal injury to the person moving the bath If the bath is going to be placed in an area where it will need to be moved fre quently a special cart can be designed to accommodate the bath making the bath much more portable Hart sells carts designed for these baths However even with a cart the bath should not be moved full of fluid The fluid can splash causing injury or if the bath and cart tip the fluid could cause damage to the surrounding area and personal injury to personnel If the bath must be moved be sure to drain the fluid to prevent any injury The side of the bath with the compressor is heavier than the tank side To safely move the bath two people are required Bath Environment The Model 7012 Bath is a precision instrument which should be located in an appropriate environment The location should be free of drafts extreme temper atures and temperature changes dirt etc The surface where the bath is placed must be level If used at higher temperatures where fluid vaporization is significant a fume hood should be used Dry out Period Before initial use after transport and any time the instrument has not been en ergized for more than 10 days the bath will need to be energi
24. ad proportional band setting pr op band pr pr 999 9 pr 15 9 Set proportional band to n pr op band n pr 8 83 Depends on Configuration Read cutout setting c utout C c 9999 x xxx c 620 C in Set cutout setting c utout n r eset Set cutout to n degrees c utout n c 500 Temperature Range Reset cutout now c utout r eset c r Read heater power po wer po po 9999 po 1 100 duty cycle Configuration Menu Probe Menu Read DO calibration parameter d0 d0 d0 999 9999 d0 25 2290 Set DO calibration parameter ton d0 n d0 25 2290 999 9999 to 999 9999 Read DG calibration parameter dg dg dg 999 9999 dg 186 9740 Set DG calibration parameter to n dg n dg 186 9740 999 9999 to 999 9999 Operating Parameters Menu Read cutout mode cm ode cm cm xxxx cm AUTO Set cutout mode cm ode r eset a uto RESET or AUTO Set cutout to be reset manually cm ode r eset cm r Set cutout to be reset cm ode a uto cm a automatically Serial Interface Menu Read serial sample setting sa mple sa sa 9 sa 1 54 10 Digital Communication Interface Interface Commands Digital Communications Commands continued Command Command Returned Acceptable Command Description Format Example Returned Example Values Set serial sampling setting to n sa mple n sa 0 0 to 4000 seconds Set serial duplex mode du plex t ull h alf FULL
25. ance temperature relation ship of the thermistor control probe These parameters may be adjusted to improve the accuracy of the bath This procedure is explained in detail in Sec tion 11 The probe parameters are accessed by pressing SET after the name of the pa rameter is displayed The value of the parameter may be changed using the UP and DOWN buttons After the desired value is reached press SET to set the parameter to the new value Pressing EXIT will cause the parameter to be skipped ignoring any changes that may have been made DO This probe parameter refers to the resistance of the control probe at 0 C Nor mally this is set for 25 2290 ohms Dg This probe parameter refers to the average sensitivity of the probe between 0 and 100 C Normally this is set for 186 9740 Operating Parameters The operating parameters menu is indicated by PAr E Operating parameters menu Press SET to enter the menu The operating parameters menu contains the cutout reset mode setting Cutout Reset Mode The cutout reset mode determines whether the cutout resets automatically when the bath temperature drops to a safe value or must be manually reset by the operator The parameter is indicated by 9 Controller Operation Serial Interface Parameters 9 12 9 12 1 Cutout reset mode parameter Press SET to access the parameter setting Normally the cutout is set for manual mode Serial In
26. art a6 kad ses es dus che ss S se See LS 4 1 Unpacking ue neo Xo 9 99 dde d buts 13 4 2 Set UDe ue e RESTER AR Rub EL EAS RO Rok ko 13 4 3 POWGE eop lere ooh SAB A as 14 4 4 Setting the Temperature 14 5 Installation 17 9 1 Bath Environment es Ro m T Yo 17 5 2 Dry out Penod 2o DR e m EEE GO 17 3 3 Bath Preparation and Filling 17 5 4 Probe em is ds A Oa ee Sw e 18 9 9 POW f di we EN RES dw e xb ss 18 6 BathUse 19 6 1 General iia e as 19 6 2 Comparison Calibration 19 6 3 Calibration of Multiple Probes 20 7 Parts and Controls 21 7 1 Front Control Panel 21 7 2 Side Panel ck RIXA ae Ru uos 22 7 3 Back Panel uu ace howe Se ee MEA RUE UE Rene 23 7 4 Bath Tank and Lid 24 8 General Operation 27 8 1 Heat Transfer Fluid 27 8 1 1 Temperature Range oko a pauses OR Bola de bmx 27 8 1 2 VISCOSILy yo 248 ach pow eee Ros m A e pence dt ge S at aed 27 8 1 3 Specific Heat ss doo amp pode x x Reb eem amp dex de qu x vg 28 8 1 4 Thermal Conductivity sica es pal modeste RR BS 28 8 1 5 Thermal Expansion e sara mmm Ro me A 28 8 1 6 Electrical Resistivity oses eo e en ae Tec me de I se tee 28 8 1 7 Fluid
27. ate temperatures above the range of water Mineral oil is relatively inexpensive At lower temperatures mineral oil is quite viscous and control may be poor At higher temperatures vapor emission becomes significant The vapors may be dangerous and a fume hood should be used As with most oils mineral oil will expand as temperature increases so be careful not to fill the bath too full that it overflows when heated The viscosity and thermal characteristics of mineral oil is poorer than water so temperature stability will not be as good Mineral oil has very low electrical conductivity Use caution with mineral oil since it is flammable and may also cause serious injury if inhaled or ingested Silicone Oils Silicone oils are available which offer a much wider operating temperature range than mineral oil Like most oils silicone oils have temperature control characteristics which are somewhat poorer than water The viscosity changes significantly with temperature and thermal expansion also occurs These oils have very high electrical resistivity Silicon oils are fairly safe These oils are relatively expensive Fluid Characteristics Charts Table 2 and Figure 6 have been created to provide help in selecting a heat ex change fluid media for your constant temperature bath The charts provide both a visual and numerical representation of most of the physical qualities impor tant in making a selection The list is not all inclusive many usable fluid
28. ater 60 0 C Low 0 04 C 0 001 C Eth Gly 50 35 0 C Low 0 05 C 0 0005 C Eth Gly 50 60 0 C Low 0 05 C 0 001 C Eth Gly 50 100 0 C High 0 4 C 0 007 C Oil 35 0 C Low 0 1 C 0 003 C Oil 60 0 C Low 0 2 C 0 002 C Oil 100 C Low 0 2 C 0 003 C 43 7012 Calibration Bath User s Guide 44 9 8 The proportional band should also be wider when the fluid viscosity is higher because of the increased response time The proportional band width is easily adjusted from the bath front panel The width may be set to discrete values in degrees C or F depending on the selected units The optimum proportional band width setting may be determined by monitoring the stability with a high resolution thermometer or with the control ler percent output power display Narrow the proportional band width to the point at which the bath temperature begins to oscillate and then increase the band width from this point to 3 or 4 times wider Table 3 lists typical propor tional band settings for optimum performance with a variety of fluids at se lected temperatures The proportional band adjustment may be accessed within the secondary menu Press SET and EXIT to enter the secondary menu and show the heater power Then press SET to access the proportional band sr fexr Access heater power in secondary menu le Pet Heater power in percent To accept the new setting and access the cutout set point press SET Pr
29. ation involves testing a probe unit under test UUT against a reference probe After inserting the probes to be calibrated into the bath al low sufficient time for the probes to settle and the temperature of the bath to stabilize One of the significant dividends of using a bath rather than a dry well to cali brate multiple probes is that the probes do not need to be identical in construc tion The fluid in the bath allows different types of probes to be calibrated at the same time However stem effect from different types of probes is not to tally eliminated Even though all baths have horizontal and vertical gradients 19 7012 Calibration Bath User s Guide 20 6 3 these gradients are minimized inside the bath work area Nevertheless probes should be inserted to the same depth in the bath liquid Be sure that all probes are inserted deep enough to prevent stem effect From research at Hart Scien tific we suggest a general rule of thumb for immersion depth to reduce the stem effect to a minimum 15 x the diameter of the UUT the sensor length Do not submerge the probe handles If the probe handles get too warm dur ing calibration at high temperatures a heat shield could be used just below the probe handle This heat shield could be as simple as aluminum foil slid over the probe before inserting it in the bath or as complicated as a specially designed reflective metal apparatus When calibrating over a wide temperature ran
30. aying the bath temperature Press UP or DOWN to adjust the set point value t 42 50 New set point value When the desired set point value is reached press SET to accept the new value and access the set point vernier If EXIT is pressed instead then any changes made to the set point will be ignored Accept new set point value Set point Vernier The set point value can only be set with a resolution of 0 002 C The user may want to adjust the set point slightly to achieve a precise bath temperature The set point vernier allows one to adjust the temperature below or above the set point by a small amount with very high resolution Each of the 8 stored set points has an associated vernier setting The vernier is accessed from the set point by pressing SET The vernier setting is displayed as a 6 digit num ber with five digits after the decimal point This is a temperature offset in de grees of the selected units C or F 0 00000 Current vernier value in C To adjust the vernier press UP or DOWN Unlike most functions the ver nier setting has immediate effect as the vernier is adjusted SET need not be pressed This allows one to continually adjust the bath temperature with the vernier as it is displayed 0 00090 i New vernier setting Next press EXIT to return to the temperature display or SET to access the temperature scale units selection 9 Controller Operation Temperature Scale U
31. c instructions Follow all safety guidelines listed in the user s manual Calibration Equipment should only be used by Trained Personnel If this equipment is used in a manner not specified by the manufacturer the protection provided by the equipment may be impaired Before initial use or after transport or after storage in humid or semi hu mid environments or anytime the instrument has not been energized for more than 10 days the instrument needs to be energized for a dry out 1 Before You Start Safety Information period of 2 hours before it can be assumed to meet all of the safety re quirements of the IEC 1010 1 If the product is wet or has been in a wet environment take necessary measures to remove moisture prior to apply ing power such as storage in a low humidity temperature chamber operat ing at 50 degree centigrade for 4 hours or more e DO NOT operate high temperature baths 500 C near flammable materi als Extreme temperatures could ignite the flammable material e Overhead clearance is required Do not place the instrument under a cabi net or other structure Always leave enough clearance to allow for safe and easy insertion and removal of probes e The instrument is intended for indoor use only BURN HAZARD e Extremely cold temperatures may be present in this equipment Freezer burns and frostbite may result if personnel fail to observe safety precau tions e High temperatures may be present in this
32. ch as Trichloroethylene or Acetone may dull or dissolve the paint The stainless steel surfaces may be cleaned with solvents as necessary to remove oils The stirring motor should be clean to allow proper cooling Normally only the outside surfaces require any attention If the inside of the motor has become heavily loaded with oily dust blow it out with compressed air Follow normal safety procedures when using pressurized gasses Periodically check the fluid level in the bath to ensure that the level has not dropped A drop in the fluid level affects the stability of the bath Changes in fluid level are dependent upon several factors specific to the environment in which the equipment is used A schedule cannot be out lined to meet each environmental setting Therefore the first year the bath should be checked weekly with notes kept as to changes in bath fluid Af ter the first year the user can set up a maintenance schedule based on the data specific to the application Heat transfer medium lifetime is dependent upon the type of medium and the environment The fluid should be checked at least every month for the first year and regularly thereafter This fluid check provides a baseline for knowledge of bath operation with clean usable fluid Once some fluids have become compromised the break down can occur rapidly Particular attention should be paid to the viscosity of the fluid A significant change in the viscosity can indicate that the f
33. e Pump 15 L min Recirculation optional Access Opening 162 mm X 292 mm 6 38 X 11 5 Depth 457 mm 18 Wetted Parts 304 stainless steel Volume 42 liters 11 2 gallons Weight 68 kg 150 Ib Size 762 mm H X 686 mm W X 401 mm D 30 X 27 X 15 8 Power 115 VAC 21096 60 Hz 1570 W 230 VAC 10 60 Hz 1570 W 50 Hz Optional A NOTE If voltage is outside 10 VAC the compressor may be damaged Check the back panel label for the correct voltage and frequency prior to energiz ing the instrument System Fuse 115 VAC 15 A 250 V slow blow 230 VAC 8 A 250 V slow blow 11 7012 Calibration Bath User s Guide 12 3 2 Heater Fuse 115 VAC 10 A 250 V fast blow 230 VAC 6 A 250 V fast blow Safety OVERVOLTAGE Installation CATEGORY II Pollution Degree 2 per IEC 61010 1 Environmental Conditions Although the instrument has been designed for optimum durability and trou ble free operation it must be handled with care The instrument should not be operated in an excessively dusty or dirty environment Maintenance and clean ing recommendations can be found in the Maintenance Section of this manual The instrument operates safely under the following conditions e ambient temperature range 5 50 C 41 122 F e ambient relative humidity maximum 80 for temperature lt 31 C de creasing linearly to 50 at 40 C e pressure 75kPa 106kPa e mains voltage within 10 of nominal e v
34. e parameters are programmed within the serial interface menu To enter the serial parameter programming mode first press EXIT while pressing SET and release to enter the secondary menu Press SET repeat edly until the display reads Pr obE This is the menu selection Press UP repeatedly until the serial interface menu is indicated with 5Ec18L Finally press SET to enter the serial parameter menu In the serial interface parame ters menu are the baud rate the sample rate the duplex mode and the linefeed parameter Baud rate The baud rate is the first parameter in the menu The display will prompt with the baud rate parameter by showing BAU g Press SET to choose to set the baud rate The current baud rate value will then be displayed The baud rate of the 7012 serial communications may be programmed to 300 600 1200 or 2400 baud The baud rate is pre programmed to 1200 baud Use UP or DOWN to change the baud rate value Press SET to set the baud rate to the new value or EXIT to abort the operation and skip to the next parameter in the menu Sample Period The sample period is the next parameter in the menu and prompted with 5Rfl PLE The sample period is the time period in seconds between temperature measurements transmitted from the serial interface If the sample rate is set to 5 the 7012 transmits the current measurement over the serial interface approxi mately every five seconds T
35. e controller configuration and calibration parameters The controller may be operated in temperature units of degrees Celsius or Fahr enheit The controller is operated and programmed from the front control panel using the four key switches and digital LED display The controller may also be optionally equipped with a serial RS 232 or IEEE 488 GPIB digital interface for remote operation Operation of the controller using the front control panel is discussed in Section 9 Operation using the digital interfaces is discussed in Section 10 When the controller is set to a new set point the bath heats or cool to the new temperature Once the new temperature is reached the bath usually takes 10 15 minutes for the temperature to settle and stabilize There may be a small over shoot or undershoot of about 0 5 C 35 9 Controller Operation Bath Temperature 9 1 9 2 Controller Operation This section discusses in detail how to operate the bath temperature controller using the front control panel Using the front panel key switches and LED dis play the user may monitor the bath temperature set the temperature set point in degrees C or F monitor the heater output power adjust the controller propor tional band set the cutout set point and program the probe calibration parame ters operating parameters serial and IEEE 488 interface configuration and controller calibration parameters Operation is summarized in Figure 7 Bath Temperature
36. ermal expansion describes how the volume of the fluid changes with temper ature Thermal expansion of the fluid used must be considered since the in crease in fluid volume as the bath temperature changes may cause overflow Excessive thermal expansion may also be undesirable in applications where constant liquid level is important Oils typically have significant thermal expansion Electrical Resistivity Electrical resistivity describes how well the fluid insulates against the flow of electric current In some applications such as measuring the resistance of bare temperature sensors it may be important that little or no electrical leakage oc cur through the fluid In this case consider a fluid with very high resistivity Fluid Lifetime Many fluids degrade over time because of evaporization water absorption gel ling or chemical breakdown Often the degradation becomes significant near the upper temperature limit of the fluid Safety When choosing a fluid always consider the safety issues associated Obviously where there are extreme temperatures there can be danger to personnel and equipment Fluids may also be hazardous for other reasons Some fluids may be considered toxic Contact with eyes skin or inhalation of vapors may cause injury A proper fume hood must be used if hazardous or bothersome vapors are produced WARNING Fluids at high temperatures May pose danger from BURNS FIRE and TOXIC fumes Use appropriate cautio
37. ers menu Press SET five times to enter the menu CTO Parameter CTO sets the calibration of the over temperature cutout This is not adjustable by software but is adjusted with an internal potentiometer For the 7012 baths this parameter should read between 120 H and L These parameters set the upper and lower set point limits of the bath DO NOT change the values of these parameters from the factory set values To do so may present danger of the bath exceeding its temperature range causing damage or fire 10 Digital Communication Interface Serial Communications 10 10 1 10 1 1 10 1 2 Digital Communication Interface If supplied with the option the 7012 bath is capable of communicating with and being controlled by other equipment through the digital interface Two types of digital interface are available the RS 232 serial interface and the IEEE 488 GPIB interface With a digital interface the bath may be connected to a computer or other equipment This allows the user to set the bath temperature monitor the tem perature and access any of the other controller functions all using remote com munications equipment In addition the heater power setting and cooling capacity may be controlled using the interface To enable the heater to be switched to high using the interface the HEATER switch must be set to the LOW position The cooling power switch must be set to OFF to enable re mote control
38. escription Canadian Standards Association Us CATI OVERVOLTAGE Installation CATEGORY II Pollution Degree 2 per IEC1010 1 re fers to the level of Impulse Withstand Voltage protection provided Equipment of OVERVOLTAGE CATEGORY II is energy consuming equipment to be supplied from the fixed installation Examples include household office and laboratory appliances The European Waste Electrical and Electronic Equipment WEEE Directive C TIC Australian EMC Mark i 2002 96 EC mark 1 2 Safety Information Use this instrument only as specified in this manual Otherwise the protection provided by the instrument may be impaired The following definitions apply to the terms Warning and Caution WARNING identifies conditions and actions that may pose hazards to the user CAUTION identifies conditions and actions that may damage the in strument being used 1 2 1 WARNINGS To avoid possible electric shock or personal injury follow these guidelines GENERAL DO NOT use the instrument for any application other than calibration work The instrument was designed for temperature calibration Any other use of the unit may cause unknown hazards to the user DO NOT use the unit in environments other than those listed in the user s guide DO NOT overfill the bath Overflowing extremely cold or hot fluid may be harmful to the operator See Section 5 3 Bath Preparation and Filling for specifi
39. essing EXIT will exit the secondary menu ignoring any changes just made to the proportional band value Accept the new proportional band setting Cutout As a protection against software or hardware fault shorted heater triac or user error the bath is equipped with an adjustable heater cutout device that shuts off power to the heater if the bath temperature exceeds a set value This protects the heater and bath materials from excessive temperatures and most impor tantly protects the bath fluids from being heated beyond the safe operating temperature preventing hazardous vaporization breakdown or ignition of the liquid The cutout temperature is programmable by the operator from the front panel of the controller It must always be set below the upper temperature limit 9 Controller Operation Controller Configuration 9 9 of the fluid and no more than 10 degrees above the upper temperature limit of the bath If the cutout is activated because of excessive bath temperature power to the heater shuts off and the bath cools The bath cools until it reaches a few degrees below the cutout set point temperature At this point the action of the cutout is determined by the setting of the cutout mode parameter The cutout has two selectable modes automatic reset or manual reset If the mode is set to auto matic the cutout automatically resets itself when the bath temperature falls be low the reset temperature allowing the bath to
40. et to 5 the bath transmits the current measurement over the serial interface approximately every five seconds The automatic sampling is disabled with a sample period of 0 The sample period is indicated by Serial sample period parameter Press SET to choose to set the sample period The current sample period value will be displayed Current sample period seconds Adjust the value with UP or DOWN and then use SET to set the sample rate to the displayed value SA 60 i New sample period Duplex Mode The next parameter is the duplex mode The duplex mode may be set to full du plex or half duplex With full duplex any commands received by the bath via the serial interface are immediately echoed or transmitted back to the device of origin With half duplex the commands are executed but not echoed The du plex mode parameter is indicated by dUPL i Serial duplex mode parameter Linefeed The final parameter in the serial interface menu is the linefeed mode This pa rameter enables on or disables off transmission of a linefeed character LF ASCII 10 after transmission of any carriage return The linefeed parameter is indicated by LF i Serial linefeed parameter 9 Controller Operation IEEE 488 Parameters 9 13 9 13 1 9 14 Press SET to access the linefeed parameter LF On i Current linefeed setting IEEE 488 Parameters Baths may optionally be fitted with an IEEE 488 GPIB in
41. ew or program the various parameters The inter face commands are discussed in Section 10 3 All commands are ASCII charac ter strings terminated with a carriage return character CR ASCII 13 IEEE 488 Communication The IEEE 488 interface is available as an option Baths supplied with this op tion may be connected to a GPIB type communication bus which allows many instruments to be connected and controlled simultaneously To eliminate noise the GPIB cable should be shielded Setup To use the IEEE 488 interface first connect an IEEE 488 standard cable to the back of the bath Next set the device address This parameter is programmed within the IEEE 488 interface menu To enter the IEEE 488 parameter programming menu first press EXIT while pressing SET and release to enter the secondary menu Press SET repeat edly until the display reaches Pr 8b This is the menu selection Press UP repeatedly until the IEEE 488 interface menu is indicated with IEEE Press SET to enter the IEEE 488 parameter menu The IEEE 488 menu contains the IEEE 488 address parameter IEEE 488 Interface Address The IEEE 488 address is prompted with Addr E55 Press SET to program the address The default address is 22 Change the device address of the bath if necessary to match the address used by the communication equipment by pressing UP or DOWN and then SET IEEE 488 Operation Commands may now be sent via the
42. f heating to the bath the user can tell if the bath is heating up to the set point cooling down or con trolling at a constant temperature Monitoring the percent heater power will let the user know how stable the bath temperature is With good control stability the percent heating power should not fluctuate more than 1 within one minute The heater power display is accessed in the secondary menu Press SET and EXIT simultaneously and release The heater power will be displayed as a percentage of full power sr fexr Access heater power in secondary menu Ip Pct Heater power in percent To exit out of the secondary menu press EXIT To continue on to the propor tional band setting function press SET Proportional Band In a proportional controller such as this the heater output power is proportional to the bath temperature over a limited range of temperatures around the set point This range of temperature is called the proportional band At the bot tom of the proportional band the heater output is 100 At the top of the pro portional band the heater output is 0 Thus as the bath temperature rises the heater power is reduced which consequently tends to lower the temperature back down In this way the temperature is maintained at a fairly constant temperature The temperature stability of the bath depends on the width of the proportional band See Figure 8 If the band is too wide the bath temperature will deviate ex
43. for instance 20 C and 80 C are chosen as the calibration tem peratures the bath may achieve an accuracy of say 0 2 C over the range 20 to 80 C Choosing 30 C and 70 C may allow the bath to have a better accuracy of maybe 0 05 C over the range 30 to 70 C but outside that range the accuracy may be only 0 5 C Measuring the Set point Error The first step in the calibration procedure is to measure the temperature errors including sign at the two calibration temperatures First set the bath to the lower set point which we will call tj Wait for the bath to reach the set point and allow 15 minutes to stabilize at that temperature Check the bath stability with the thermometer When both the bath and the thermometer have stabilized measure the bath temperature with the thermometer and compute the tempera ture error err which is the actual bath temperature minus the set point temper ature If for example the bath is set for a lower set point of tj 220 C and the bath reaches a measured temperature of 19 7 C then the error is 0 3 C Next set the bath for the upper set point tj and after stabilizing measure the bath temperature and compute the error erry For our example we will suppose 59 7012 Calibration Bath User s Guide 60 11 4 the bath was set for 80 C and the thermometer measured 80 1 C giving an error of 0 1 C Computing DO and DG Before computing the new values for DO and DG the current values must be k
44. g on the end of the drain tube This drain plug is to be fluid tight until the time of draining The following information is helpful when draining the bath Always use a container capable of holding the entire load of fluid Us ing an adequate size about 8 gallons or 1 cubic foot heat proof fluid container is extremely important Use safety equipment as appropriate 1 Water and low viscosity fluids Drain at room temperature Normal care must be taken for fluids that may have corrosive or damaging effects on the surrounding facility or equipment 64 12 Maintenance Draining the Bath 2 High viscosity oils The fluid should be sufficiently low in viscosity to drain efficiently Some oils such as 710 silicone oil may need to be heated to 80 C to be fluid enough to drain well The viscosity affects how rapidly it drains as well as how well it flows off of the walls Heat proof containers and appropriate safety equipment such as face shields gloves and body covering are recommended A WARNING Extreme danger of BURNS and FIRE Use safety equipment use proper equipment and have fire safety equipment standing by 65 13 Troubleshooting Troubleshooting 13 13 1 Troubleshooting This section contains information on troubleshooting and CE Comments This information pertains to a number of bath models and certain specifics may not pertain to your model Troubleshooting In the event that the instrument appears to functi
45. ge better results can generally be achieved by starting at the highest temperature and progressing down to the lowest temperature Probes can be held in place in the bath by using probe clamps or drilling holes in the access cover Other fixtures to hold the probes can be designed The ob ject is to keep the reference probe and the probe s to be calibrated as closely grouped as possible in the working area of the bath Bath stability is maximized when the bath working area is kept covered In preparing to use the bath for calibration start by e Placing the reference probe in the bath working area e Placing the probe to be calibrated the UUT in the bath working area as close as feasibly possible to the reference probe Calibration of Multiple Probes Fully loading the bath with probes increases the time required for the tempera ture to stabilize after inserting the probes Using the reference probe as the guide be sure that the temperature has stabilized before starting the calibration 7 Parts and Controls Front Control Panel 7 Parts and Controls 7 1 Front Control Panel The following controls and indicators are present on the controller front panel see Figure 2 below 1 the digital LED display 2 the control buttons 3 the bath on off power switch 4 the control indicator light 5 the heater power switch and 6 the cooling power switch 1 The digital display is an important part of the temperature contro
46. h to LOW and 2 switching the refrigeration switch to OFF Otherwise the interface would not be able to switch these functions off The 7012 bath has four control functions with the digital interface These are heater power high low cooling on off ex pansion valve on off and back pressure valve on off Heater Control To control the heater with the digital interface the front panel heater switch must be set to LOW 500 W The heater function is controlled with the F1 command Setting the F1 parameter to 0 sets the heater to LOW 500 W and setting it to 1 sets the heater to HIGH 1000 W Sending F1 with no value causes the controller to return a value showing what the heater setting is When the heater setting is changed a pop is heard as the heater relay opens or closes Cooling Control To control the refrigeration power with the digital interface the front panel re frigeration switch must be off The refrigeration power function is controlled with the F2 command Setting the F2 value to 0 turns the refrigeration off and setting it to 1 turns it on F2 alone returns 0 or 1 showing the state of the refrigeration power control The F3 command controls the high and low cooling temperature range or expansion valves As discussed in Section 7 2 this valve adjusts the cooling temperature which sets the cooling capacity Setting F3 to 1 opens the valve on or high and 0 closes the valve off or low A co
47. he automatic sampling is disabled with a sample period of 0 Press SET to choose to set the sample period Adjust the period with UP or DOWN and then use SET to set the sample rate to the dis played value Duplex Mode The next parameter is the duplex mode indicated with d UPL The duplex mode may be set to half duplex HALF or full duplex FULL With full duplex any commands received by the thermometer via the serial interface are immediately echoed or transmitted back to the device of origin With half du plex the commands are executed but not echoed The default setting is full du plex The mode may be changed using UP or DOWN and pressing SET Linefeed The final parameter in the serial interface menu is the linefeed mode This pa rameter enables On or disables OFF transmission of a linefeed charac ter LE ASCII 10 after transmission of any carriage return The default setting is with linefeed on The mode may be changed using UP or DOWN and pressing SET 10 Digital Communication Interface IEEE 488 Communication 10 1 3 10 2 10 2 1 10 2 1 1 10 2 2 10 3 Serial Operation Once the cable has been attached and the interface set up properly the control ler immediately begins transmitting temperature readings at the programmed rate The set point and other commands may be sent to the bath via the serial interface to set the bath and vi
48. he battery is spent and should be replaced Con tact an Authorized Service Center for assistance 5 After replacing the battery you must reprogram the calibration and user adjustable parameters into the controller Comments EMC Directive Hart Scientifics equipment has been tested to meet the European Electromag netic Compatibility Directive EMC Directive 89 336 EEC The Declaration of Conformity for your instrument lists the specific standards to which the unit was tested Low Voltage Directive Safety In order to comply with the European Low Voltage Directive 73 23 EEC Hart Scientific equipment has been designed to meet the IEC 1010 1 EN 61010 1 and the IEC 1010 2 010 EN 61010 2 010 standards
49. he command is returned followed by a carriage return and linefeed Then the value is returned as indicated in the RETURNED column 55 7012 Calibration Bath User s Guide 56 10 4 10 4 1 10 4 2 may be used Commands may be abbreviated to the minimum number of letters which determines a unique command A command may be used to either set a parameter or display a parameter depending on whether or not a value is sent with the command following a character For example s lt CR gt will return the current set point and s 50 00 lt CR gt will set the set point to 50 00 degrees In the following list of commands characters or data within brackets and are optional for the command A slash denotes alternate characters or data Numeric data denoted by n may be entered in decimal or exponential notation Characters are shown in lower case although upper case may be used Spaces may be added within command strings and will simply be ignored Backspace BS ASCII 8 may be used to erase the previous character A termi nating CR is implied with all commands Power Control Functions The digital interface is capable of controlling the heating and cooling functions so that the bath can be remotely operated at any temperature within the range of the bath To allow the interface to control the heating and the cooling the front panel controls are disabled by 1 switching the heater switc
50. he right to invoice Buyer for importation costs of repairs replacement parts when product purchased in one country is submitted for repair in another country Hart s warranty obligation is limited at Hart s option to refund of the purchase price free of charge re pair or replacement of a defective product which is returned to a Hart authorized service center within the warranty period To obtain warranty service contact your nearest Hart authorized service center or send the product with a description of the difficulty postage and insurance prepaid FOB Destination to the nearest Hart au thorized service center Hart assumes no risk for damage in transit Following warranty repair the prod uct will be returned to Buyer transportation prepaid FOB Destination If Hart determines that the failure was caused by misuse alteration accident or abnormal condition or operation or handling Hart will provide an estimate or repair costs and obtain authorization before commencing the work Following repair the product will be returned to the Buyer transportation prepaid and the Buyer will be billed for the repair and return transportation charges FOB Shipping Point THIS WARRANTY IS BUYER S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IM PLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE HART SHALL NOT BE LIABLE FOR ANY SPECIAL INDIRECT INCIDENTAL
51. ibrations in the calibration environment should be minimized e altitude does not effect the performance or safety of the unit e indoor use only 4 Quick Start Unpacking 4 4 1 4 2 Quick Start A CAUTION READ SECTION 6 ENTITLED BATH USE before placing the bath in service Incorrect handling can damage the bath and void the warranty This section gives a brief summary of the steps required to set up and operate the 7012 bath This should be used as a general overview and reference and not as a substitute for the remainder of the manual Please read Section 5 through 7 carefully before operating the bath Unpacking Unpack the bath carefully and inspect it for any damage that may have oc curred during shipment If there is shipping damage notify the carrier immediately Verify that all components are present e 7012 Bath e Controller Probe e Access Hole Cover e User s Guide e Report of TEst e Fill Hole Cover e Drain Elbow If you are missing any item please contact an Authorized Service Center Set Up Set up of the bath requires careful unpacking and placement of the bath filling the bath with fluid installing the probe and connecting power Consult Section 5 for detailed instructions for proper installation of the bath Be sure to place the bath in a safe clean and level location Fill the bath tank with an appropriate liquid For operation at moderate bath temperatures clean distilled water works we
52. ific to the fluid selected Generally baths are set to one temperature and used to calibrate probes only at that single temperature This means that the type of bath fluid does not have to change Additionally the bath can be left energized reducing the stress on the system The bath generates extreme temperatures Precautions must be taken to prevent personal injury or damage to objects Probes may be extremely hot or cold when removed from the bath Cautiously handle probes to prevent personal in jury Carefully place probes on a heat cold resistant surface or rack until they are at room temperature It is advisable to wipe the probe with a clean soft cloth or paper towel before inserting it into another bath This prevents the mixing of fluids from one bath to another If the probe has been calibrated in liquid salt carefully wash the probe in warm water and dry completely before transferring it to another fluid Always be sure that the probe is completely dry before in serting it into a hot fluid Some of the high temperature fluids react violently to water or other liquid mediums Be aware that cleaning the probe can be danger ous if the probe has not cooled to room temperature Additionally high temper ature fluids may ignite the paper towels if the probe has not been cooled For optimum accuracy and stability allow the bath adequate stabilization time after reaching the set point temperature Comparison Calibration Comparison calibr
53. igeration may be damaged or the lifetime shortened if the set point temperature is set above 60 C for more than one hour with the refrigeration manually on Ensure that the refrigeration is off when the unit is used above 60 C The Factory Reset Sequence should be performed only by authorized personnel if no other action is successful in correcting a malfunction You must have a copy of the most recent Report of Test to restore the test pa rameters DO NOT operate this instrument in an excessively wet oily dusty or dirty environment The unit is a precision instrument Although it has been designed for opti mum durability and trouble free operation it must be handled with care Position the unit before the tank is filled with fluid Use the handles pro vided to move the unit Due to the weight of the compressor it may re quire two people to safely move the bath If two people are used place one person in the front and one person in the back of the unit carefully slide hands under the unit and lift in unison The area containing the com pressor will be heavier than the rest of the unit Do not move a unit filled with fluid Most probes have handle temperature limits Be sure that the probe handle temperature limit is not exceeded in the air above the instrument 1 Before You Start Authorized Service Centers 1 3 e The instrument and any thermometer probes used with it are sensitive in struments that can be easily damaged A
54. isplay flashes cutout and an incorrect process temper ature Check that the control probe has not been struck bent or damaged If the cause of the problem remains un known contact an Authorized Service Center see Sec tion 1 3 on page 5 for assistance The controller shows that the out put power is steady but the pro cess temperature is unstable Possible causes are an improper proportional band setting or the fluid being used e f the bath temperature does not achieve the expected degree of stability when measured using a thermometer try adjusting the proportional band to a narrower width as discussed in Section 9 7 Proportional Band Check to ensure the fluid has not deteriorated or is not too thick The controller alternately heats for a while then cools The bath is not stable and the duty cycle is not constant The proportional band being too narrow typically causes this oscillation Increase the width of the proportional band until the temperature stabilizes as discussed in Section 9 7 Proportional Band The controller erratically heats then cools control is unstable If both the bath temperature and output power do not vary periodically but in a very erratic manner the problem may be excess noise in the system Noise due to the control sensor should be less than 0 001 C However if the probe has been damaged or has developed an inter mittent short erratic behavior may exist The probe i
55. it of allowable viscosity Viscosities greater than this cause very poor control stability and may also overheat or damage the stirring motor With oils viscosity may vary greatly with temperature Viscosity in creases as temperature decreases When fluid viscosity increases stability per formance of the unit may decrease When using fluids with higher viscosities the controller proportional band may need to be increased to compensate for the reduced response time Otherwise the temperature may begin to oscillate Ensure that stirring occurs at all temperatures 27 7012 Calibration Bath User s Guide 28 8 1 3 Specific Heat Specific heat is the measure of the heat storage ability of the fluid Specific heat though to a lesser degree also affects the control stability and the heating and cooling rates Generally a lower specific heat causes slightly better control stability and quicker heating and cooling With fluids with higher specific heat the controller may require a decreased proportional band to compensate for the decrease in sensitivity of the bath temperature to heat input Thermal Conductivity Thermal conductivity measures how easily heat flows through the fluid Ther mal conductivity of the fluid affects the control stability temperature unifor mity and probe temperature settling time Fluids with higher conductivity distribute heat more quickly and evenly improving bath performance Thermal Expansion Th
56. ll Carefully pour the fluid into the bath tank through the large rectangular access hole above the tank avoiding spilling any fluid The fluid must not exceed a height of 1 2 inch below the bath lid The control probe must be inserted through the lid into the bath and plugged into the socket at the back of the bath 13 7012 Calibration Bath User s Guide 4 3 4 4 Power Plug the bath power cord into a mains outlet of the proper voltage frequency and current capability Refer to Section 3 1 Specifications for power require ment details Refer to and read the WARNING at the front of this manual con cerning brownout and over voltage protection Set the HEATER switch on the front panel to position LOW and turn the bath on using the front panel POWER switch The bath will turn on and be gin to heat or cool to reach the previously programmed temperature set point The front panel LED display will indicate the actual bath temperature Setting the Temperature In the following discussion a solid box around the word SET UP EXIT or DOWN indicates the panel button while the dotted box indicates the display reading Explanation of the button or display reading are to the right of each button or display value To view or set the bath temperature set point proceed as follows The front panel LED display normally shows the actual bath temperature 24 68 Bath temperature display When SET is pressed
57. ller be cause it not only displays set and actual temperatures but also displays various bath functions settings and constants The display shows temperatures in val ues according to the selected scale units C or F 2 The control buttons SET DOWN UP and EXIT are used to set the bath temperature set point access and set other operating parameters and access and set bath calibration parameters A brief description of the functions of the buttons follows SET Used to display the next parameter in a menu and to set parameters to the displayed value DOWN Used to decrement the displayed value of settable parameters UP Used to increment the displayed value EXIT Used to exit from a menu When EXIT is pressed any changes made to the displayed value are ignored 3 The on off switch controls power to the entire bath assembly It powers the stirring motor and the bath controller heater circuit 4 The control indicator is a two color light emitting diode This indicator lets the user visually see the ratio of heating to cooling When the indicator is red 7012 HIGH PRECISION BATH 10 C to 110 C Hart Scientific HEATER 1 4 MODE HEATING COOLING Figure 2 Front Panel 21 7012 Calibration Bath User s Guide the heater is ON When the indicator is green the heater is OFF and the bath is cooling 5 The heater power switch is used to select the appropriate heater power lev els for heati
58. luid is contaminated being used out side of its temperature limits contains ice particles or is close to a chemi cal breakdown Once data has been gathered a specific maintenance schedule can be outline for the instrument Refer to the General Operation section Section 8 for more information about the different types of flu ids used in calibration baths If a hazardous material is spilt on or inside the equipment the user is re sponsible for taking the appropriate decontamination steps as outlined by the national safety council with respect to the material MSDS sheets ap plicable to all fluids used in the baths should be kept in close proximity to the instrument 63 7012 Calibration Bath User s Guide e Ifthe mains supply cord becomes damaged replace it with a cord with the appropriate gauge wire for the current of the bath If there are any questions contact an Authorized Service Center for more information e Before using any cleaning or decontamination method except those rec ommended by Hart users should check with an Authorized Service Cen ter to be sure that the proposed method will not damage the equipment e If the instrument is used in a manner not in accordance with the equip ment design the operation of the bath may be impaired or safety hazards may arise WARNING When checking the over temperature cutout be sure that the temperature limits of the bath fluid are not exceeded Exceeding the tem perat
59. lways handle these devices with care Do not allow them to be dropped struck stressed or overheated COLD BATHS e Refrigerated baths require that the condensing coil be cleaned periodi cally Accumulation of dust and dirt on the condenser will result in pre mature failure of the compressor e This bath has been equipped with a brownout and over voltage protection device as a safety feature to protect the system components e Mode of Operation This bath needs to be plugged into the line voltage for at least two minutes before operation This is only necessary for the first time that the bath is energized or when it is moved from one location to another Turning the bath ON or OFF does not trigger the delay e Ifa High Low voltage condition exists for longer than 5 seconds the bath will be de energized The Mains Out of Range light on the back of the bath will be lit indicating a fault condition Re energization is auto matic upon correction of the fault condition and after a delay cycle of about two minutes If a fault condition exists upon application of power the bath will not energize Under and Over Voltage Protection at 115 VAC Voltage Cutout 12 5 101 129 VAC Voltage Cut In 7 5 96 106 124 VAC Under and Over Voltage Protection at 230 VAC Voltage Cutout 12 5 203 257 VAC Voltage Cut In 7 5 213 247 VAC Authorized Service Centers Please contact one of the following authorized Service Centers
60. mmand with no value re turns the current value With the valve closed the cooling temperature is set with the cooling temperature knob labeled LOW This should be adjusted for approximately 9 14 psi if the bath is to be used as low as 10 C The knob la 10 Digital Communication Interface Power Control Functions beled HIGH controls the cooling temperature when the expansion valve is open or on This should be adjusted for approximately 45 50 psi These values are typical but may be adjusted as required for specific applications The low range must be set to a lower pressure temperature than the high range valve The F4 command controls the back pressure valve When the valve is open the cooling capacity is significantly reduced This valve should normally be left off closed throughout the operating range of the bath Table 5 summarizes the control functions for heating and cooling Table 6 shows the recommended control settings for each operating temperature range The ranges may need to be adjusted depending on the bath application Table 5 Serial Power Control Functions Function Command 0 1 Heater F1 low high Refrigeration F2 off on Expansion valve F3 open closed Back pressure FA open closed Table 6 Temperature Range Control Functions Range Heater Refr Exp 10 to 15 C low on open 15 to 40 C low on closed 40 to 110 C low high off open 57 11 Calibration Procedure Calibration Points
61. n and safety equipment 8 General Operation Heat Transfer Fluid 8 1 10 8 1 10 1 8 1 10 2 8 1 10 3 Fluids may be flammable and require special fire safety equipment and proce dures An important characteristic of the fluid to consider is the flash point The flash point is the temperature at which there is sufficient vapor given off so that when there is sufficient oxygen present and an ignition source is applied the va por will ignite This does not necessarily mean that fire will be sustained at the flash point The flash point may be either of the open cup or closed cup type Either condition may occur in a bath situation The closed cup temperature is always the lower of the two The closed cup represents the contained vapors in side the tank and the open cup represents the vapors escaping the tank Oxygen and an ignition source will be less available inside the tank Environmentally hazardous fluids require special disposal according to applica ble federal or local laws after use Cost Cost of bath fluids may vary greatly from cents per gallon for water to hun dreds of dollars per gallon for synthetic oils Cost may be an important consid eration when choosing a fluid Commonly Used Fluids Below is a description of some of the more commonly used fluids and their characteristics Water Water is often used because of its very low cost availability and excellent tem perature control characteristics Water has
62. nd cost Use the fluid chart in the manual to choose the type of fluid that is best suited for your intended purpose Temperature Range One of the most important characteristics to consider is the temperature range of the fluid Few fluids work well throughout the complete temperature range of the bath The temperature at which the bath is operated must always be within the safe and useful temperature range of the fluid The lower tempera ture range of the fluid is determined by the freeze point of the fluid or the tem perature at which the viscosity becomes too great The upper temperature is usually limited by vaporization flammability or chemical breakdown of the fluid Vaporization of the fluid at higher temperatures may affect temperature stability because of cool condensed fluid dripping into the bath from the lid The bath temperature should be limited by setting the safety cut out so that the bath temperature cannot exceed the safe operating temperature limit of the fluid Viscosity Viscosity is a measure of the thickness of a fluid how easily it can be poured and mixed Viscosity affects the temperature stability of the bath With low vis cosity fluid mixing is better which creates a more uniform temperature throughout the bath This improves the bath response time which allows it to maintain a more constant temperature For good control the viscosity should be less than 10 centistokes 50 centistokes is about the upper lim
63. ng and controlling the bath at various temperatures 6 The cooling power switch controls power to the cooling compressor and cooling fan 7 2 Side Panel The side panel has three features see Figure 3 1 the back pressure valve 2 the cooling temperature regulating valve and 3 the cooling temp gauge With the interface option an extra cooling valve HIGH is provided 1 The back pressure valve adjustment is used to control the amount of cooling supplied to the system This valve reduces the cooling capacity by restricting the flow of refrigerant to the bath allowing the adjustment of the heating to cooling percentage Under normal operation the valve should be fully open counter clockwise Cooling Back Pressure O Standard O Cooling WESS 71 Back Pressure Low Hg With Interface optional Figure 3 Refrigeration Controls Side Panel 22 7 Parts and Controls Back Panel 7 3 2 The cooling temperature regulating valve is used to adjust the tempera ture at which the refrigerant evaporates which determines cooling effi ciency Refer to the label below the gauge for approximate psi and evaporative temperature settings The following table is reproduced from the label For this bath Set the Cooling Temp Valve to this pressure Control Temperature NC SE Nominal Cooling PSIG 10 14 4 7 z5 23 9 2 0
64. nits 9 4 SET Access scale units Temperature Scale Units The temperature scale units of the controller may be set by the user to degrees Celsius C or Fahrenheit F These units are used in displaying the bath temperature set point vernier proportional band and cutout set point The temperature scale units selection is accessed after the vernier adjustment function by pressing SET From the temperature display function access the units selection by pressing SET 4 times C 25 00 i Set point value SET Access vernier 0 00000 Vernier setting Press SET to accept the new selection and resume displaying the bath temperature SET Set the new units and resume temperature display 41 7012 Calibration Bath User s Guide 42 9 5 9 6 9 7 Secondary Menu Functions which are used less often are accessed within the secondary menu The secondary menu is accessed by pressing SET and EXIT simulta neously and then releasing The first function in the secondary menu is the heater power display Heater Power The temperature controller controls the temperature of the bath by pulsing the heater on and off The total power being applied to the heater is determined by the duty cycle or the ratio of heater on time to the pulse cycle time This value may be estimated by watching the red green control indicator light or read di rectly from the digital display By knowing the amount o
65. nown The values may be found by either accessing the probe calibration menu from the controller panel or by inquiring through the digital interface The user should keep a record of these values in case they may need to be re stored in the future The new values DO and DG are computed by entering the old values for DO and DG the calibration temperature set points tj and ty and the temperature errors err and erry into the following equations _ err ty D0 err t DO pp DO ly t DG err err ES ipa ty t If for example DO and DG were previously set for 25 229 and 186 9740 re spectively and the data for ty ty err and erry were as given above then the new values DO and DG would be computed as 25 831 and 188 220 respec tively Program the new values DO and DG into the controller The new con stants will be used the next time the bath temperature is set Check the calibration by setting the temperature to t and ty and measuring the errors again If desired the calibration procedure may be repeated again to further im prove the accuracy Calibration Example The bath is to be used between 25 and 75 C and it is desired to calibrate the bath as accurately as possible for operation within this range The current val ues for DO and DG are 25 229 and 186 974 respectively The calibration points are chosen to be 25 00 and 75 00 C The measured bath temperatures are 24 869 and 74 901 C respec
66. oblem is not the probe erroneous data in mem ory may be the cause Re initialize the memory as dis cussed in the problem The display flashes cutout and an incorrect process temperature If the problem re mains the cause may be a defective electronic compo nent contact an Authorized Service Center see Section 1 3 on page 5 for assistance 13 Troubleshooting Troubleshooting Problem Causes and Solutions The controller controls or at tempts to control at an inaccurate temperature The controller operates normally except when controlling at a speci fied set point At this set point the temperature displayed does not agree with the temperature measured by the user s reference ther mometer to within the specified accuracy This problem may be caused by an actual difference in temperature between the points where the control probe and thermometer probe measure tempera ture by erroneous bath calibration parameters or by a damaged con trol probe Check that the bath has an adequate amount of fluid in the tank and that the stirrer is operating properly Check that the thermometer probe and control probe are both fully inserted into the bath to minimize temperature gradient errors Check that the calibration parameters are all correct ac cording to the Report of Test If not re program the con stants The memory backup battery may be weak causing errors in data as described in the problem The d
67. ok pisse tu ee ee esse 21 Refrigeration Controls Side Panel 22 Back Panels use sce P Rees A Se Res BLS 24 Drain Location and Lid Options 25 Chart of various bath fluids and their properties 31 Table of various bath fluids and their properties 32 Controller Operation Flowchart 38 Proportional Band Fluid Table 43 Bath temperature fluctuation at various proportional band settings 43 Serial Communications Cable Wiring 51 Interface Command Summary 54 Digital Communications Commands continued 55 Serial Power Control Functions 57 Temperature Range Control Functions 57 Sample calibration computations 61 1 Before You Start Symbols Used 1 1 Before You Start Symbols Used Table 1 lists the International Electrical Symbols Some or all of these symbols may be used on the instrument or in this manual Table 1 International Electrical Symbols Symbol Description NU AC Alternating Current e AC DC Battery M MA CE Complies with European Union Directives DC Double Insulated Electric Shock Fuse PE Ground Hot Surface Burn Hazard Read the User s Manual Important Information Off O gt Ol eH On 7012 Calibration Bath User s Guide Symbol D
68. on Resistivity No Limit Limit Point centistokes Gravity ca s cm C cm cm C 10 0 cm Halocarbon 0 8 90 C v 70 C e NONE 5 7 50 C 1 71 40 C 0 2 0 0004 0 0011 5019 0 8 40 C 0 5 70 C Methanol 96 C fr 60 C b 54 C 1 3 35 C 0 810 0 C 0 6 0 0005 20 C 0 0014 25 C 0 66 0 C 0 792 20 C 0 45 20 C Water 0 C fr 95 C b NONE 1 25 C 1 00 1 00 0 0014 0 0002 25 C 0 4 75 C Ethylene 35 C fr 110 C b NONE 7 0 C 1 05 0 8 0 C 0 001 Glycol 50 2 50 C 5020 0 7 100 C Mineral Oil 40 C v 190 C fl 190 C 15 75 C 0 87 25 C 0 48 25 C 0 00025 25 C 0 0007 50 C 5 25 C 5 125 C 0 84 75 C 0 53 75 C 0 81 125 C 0 57 125 C Dow Corning 40 C v 133 C fl cc 133 C 5 25 C 0 92 25 C 0 4 0 00028 25 C 0 00105 1000 25 C 200 5 10 150 C Silicone Oil Dow Corning 35 C v 165 C fl cc 165 C 100 25 C 0 934 25 C 0 43 40 C 0 00032 25 C 0 00108 1000 25 C 200 10 3 135 C 0 45 100 C 50 150 C 5012 0 482 200 C Dow Corning 7 C v 230 C fl cc 230 C 200 25 C 0 949 25 C 0 370 40 C 0 00034 25 C 0 00107 1000 25 C 200 20 0 393 100 C 50 150 C 5013 0 420 200 C Dow Corning 25 C v 280 C fl cc 280 C 20 25 C 0 96 25 C 0 4 0 00037 25 C 0 00104 1000 25 C 200 50 50 150 C Silicone Oil Dow Corning 550 70 C v 232 C fl cc 232 C 50 70 C 1 07 25 C 0 358 40
69. on abnormally this section may help to find and solve the problem Several possible problem conditions are described along with likely causes and solutions If a problem arises please read this section carefully and attempt to understand and solve the problem If the probe seems faulty or the problem cannot otherwise be solved contact an Authorized Service Center see Section 1 3 on page 5 for assistance Be sure to have the instrument model number serial number voltage and problem de scription available Problem Causes and Solutions The heater indicator LED stays The display does not show ut o UE nor displays an incorrect bath red but the temperature does not temperature and the controller otherwise appears to operate normally increase The problem may be insufficient heating no heating at all or too much cooling The heater power setting being too low especially at higher operating One or more burned out heaters or blown heater fuses may also cause this problem If the heaters seem to be burned out contact an Authorized Service Center see Section 1 3 on page 5 for assistance The controller display flashes The display flashs u o ut alternately with the process Cut out and the heater does temperature not operate e f the process temperature displayed seems grossly in error consult the following problem The display flashes Cuk out and an incorrect process temperature
70. on pages 24 and 25 may be used to remove fluid from the bath During operation of the bath the drain must be closed Temperature Controller The bath temperature is controlled by Hart Scientific s unique hybrid digi tal analog temperature controller The controller offers the tight control stability of an analog temperature controller as well as the flexibility and programmabil ity of a digital controller The bath temperature is monitored with a linear thermistor sensor in the control probe The signal is electronically compared with the programmable reference 8 General Operation Temperature Controller signal amplified and then fed to a pulse width modulator circuit which con trols the amount of power applied to the bath heater The bath is operable within the temperature range given in the specifications For protection against solid state relay failure or other circuit failure the microcontroller automatically turns off the heater with a second mechanical re lay anytime the bath temperature is more than a certain amount above the set point temperature As a second protection device the controller is also equipped with a separate thermocouple temperature monitoring circuit which shuts off the heater if the temperature exceeds the cut out set point The controller allows the operator to set the bath temperature with high resolu tion set the cut out adjust the proportional band monitor the heater output power and program th
71. pplied with a serial RS 232 interface the interface cable attaches to the back of the bath at the connector labeled RS 232 7 If the bath is supplied with a GPIB IEEE 488 interface the interface ca ble attaches to the back of the bath at the connector labeled IEEE 488 7 4 Bath Tank and Lid There are two different types of lids They both have the same overall dimen sions but the optional lid see Figure 5 has a recirculating pump and the stan dard lid has a stirring motor with rectangular access hole Their features are described with reference to figure numbers as follows 24 7 Parts and Controls Bath Tank and Lid D 2 3 3 Standard Lid Optional Pump Lid The top half of the latch attaches the lid to the bath There are two latches one on the front and one on the back The thermometer liquid level is a hole in the lid for filling and removing of liquid checking liquid level and for mounting a thermometer A hole may be drilled in the rubber stopper supplied for inserting a thermometer into the bath The rectangular access hole on the standard lid may be used to insert the users device to be thermostatted To obtain specified control levels this hole must be covered to prevent thermal disturbance to the bath Covers may be purchased separately from Hart Scientific The circulation inlet outlet on the pump lid is the access area or the in let and outlet for the circulation pump
72. roller to execute the many operating functions User interface is provided by the 8 digit LED display and four key switches Digital remote communications is optionally available with a RS 232 or IEEE 488 interface The tank for the 7012 is stainless steel and holds 36 liters There are two lids available the standard lid with a rectangular access hole and an optional lid with a recirculating pump see Figure 5 1 1 i m 1 1 i P 1 EI 1 1 i 4 amp 5 1 1 E i 1 1 i i Pd i 1 Heol i 1 gebe 1 1 i Mee re ced 1 i be s 1 1 1 1 1 1 1 1 i e oe aoe sore eee eer aaa el Figure 1 Bath Assembly 3 Specifications and Environmental Conditions Specifications Specifications and Environmental Conditions Specifications Range 10 C to 110 C 14 F to 230 F Stability 0 0008 C at 0 C ethanol 0 0008 C at 25 C water 0 003 C at 100 C oil 5012 Uniformity 0 003 C at 0 C ethanol 0 002 C at 25 C water 0 004 C at 100 C oil 5012 Temperature Digital display with push button data entry Setting Set point 0 002 C high resolution mode 0 00003 C Resolution Display 0 01 C Resolution Digital Setting 1 C Accuracy Digital Setting 0 005 C Repeatability Heaters 500 and 1000 Watts Safety Cutout Factory set high temperature Temperature 0 2m C Drift per C Ambient or 10 VAC lin
73. s located inside the stirrer motor cover Check for a damaged probe or poor connection between the probe and bath Intermittent shorts in the heater or controller electronic circuitry may also be a possible cause Contact an Au thorized Service Center see Section 1 3 on page 5 for assistance 69 7012 Calibration Bath User s Guide 70 13 2 13 2 1 13 2 2 Problem Causes and Solutions The bath does not achieve low temperatures Too much heating or not enough cooling can cause this problem Check that the control indicator glows green showing that the controller is attempting to cool The heaters may be disabled as a test by temporarily removing the heater fuses The controller does not maintain controller parameters or parame ters are reset each time the power to the unit is removed Note Before performing the memory check you need to record the controller calibration parameters found in the CAL menu of the instru ment and any user adjusted parameters that you have changed such as the programmable set points and proportional band Memory Check Doing a memory check is the easiest way to verify the ability of the battery to maintain controller parameters 1 Power off the instrument 2 Disconnect the instrument from AC power for 10 seconds 3 Reconnect the AC power and power on the instrument 4 f the display shows InIT and or the cycle count shows a low num ber such as 0002 t
74. s may not have been shown in this listing Limitations and Disclaimer Every effort has gone into making these charts accurate however the data here does not imply any guarantee of fitness of use for a particular application Working near the limits of a property such as the flash point or viscosity limit can compromise safety or serviceability Sources of information sometimes vary for particular properties Your company s safety policies as well as per sonal judgment regarding flash points toxicity etc must also be considered You are responsible for reading the Material Safety Data Sheets and making a judgment here Cost may require some compromises as well Hart Scientific cannot be liable for the suitability of application or for any personal injury damage to equipment product or facilities in using these fluids The charts include information on a variety of fluids which are often used as heat transfer fluid in baths Because of the temperature range some fluids may not be useful with your bath 8 General Operation Heat Transfer Fluid 100 C orc Silicone Oil 5017 Silicone Oil 5014 Silicone Oil 5013 Silicone Oil 5012 Silicone Oil 5010 HFE 7500 5023 Halocarbon 5019 Mineral Oil 5011 Water Methanol Ethanol Ethylene Glycol 50 50 with H20 5020 Dynalene HF LO 5022 Bath Salt 5001 100 C 200 C 300 C 400 C 500 C 600 C 10cs E FR Pure FL 12
75. should be used This point is very subjective in nature and is impacted by individual tolerance to different fumes and smells how well the bath is covered the surface area of the fluid in the bath the size and ventilation of the facility where the bath is located and others We assume the bath is well covered at this point This is also subject to company policy Flash Point The point at which ignition may occur See flash point discussion in Section 8 1 8 The point shown may be either the open or closed cup flash point Boiling Point At the boiling point of the fluid the temperature stability is diffi cult to maintain Fuming is excessive Excessive amounts of heater power may be required because of the heat of vaporization Decomposition All high temperature fluids may be reach a temperature point at which decomposition of some form will begin While it always begins slowly at some lower temperature the rate can increase to the point of danger or im practicality at a higher temperature Stirring Stirring of the bath fluid is very important for stable temperature control The fluid must be mixed well for good temperature uniformity and fast controller response The stirrer is precisely adjusted for optimum performance Power Power to the bath is provided by an AC mains supply Refer to Section 3 1 Specifications for power requirement details Power to the bath passes through a filter to prevent switching spikes from being tran
76. smitted to other equipment Refer to and read the WARNING at the front of this manual concerning brown out and over voltage protection To turn on the bath switch the control panel power switch to the ON position The stir motor will turn on the LED display will begin to show the bath tem perature and the heater will turn on or off until the bath temperature reaches the programmed set point When powered on the control panel display briefly shows a four digit number This number indicates the number of times power has been applied to the bath Also briefly displayed is data which indicates the controller hardware configu ration This data is used in some circumstances for diagnostic purposes Heater The power to the bath heater is precisely controlled by the temperature control ler to maintain a constant bath temperature Power is controlled by periodically switching the heater on for a certain amount of time using a solid state relay 33 7012 Calibration Bath User s Guide 34 8 5 8 6 8 7 The front panel red green control indicator shows the state of the heater The control indicator glows red when the heater is on and glows green when the heater is off The indicator will pulse constantly when the bath is maintaining a stable temperature The heater has two power level settings The HIGH heater power setting is used to quickly heat up the bath fluid to the desired operating temperature The HIGH heater power set
77. st are accurate Cycle the power off disconnect the bath from AC and then restart the bath The controller may need to be reset Perform the follow ing Factory Reset Sequence Factory Reset Sequence Hold the SET and EXIT but tons down at the same time while powering up the instrument The instrument display shows n E the model number and the firmware version Each of the controller parameters and calibration constants must be reprogrammed The values can be found on the Report of Test that was shipped with the instrument e If initializing the memory does not remedy the problem there may be a failed electronic component Contact an Authorized Service Center see Section 1 3 on page 5 for assistance The displayed process tempera ture is in error and the controller remains in the cooling or the heating state at any set point value Possible causes may be either a faulty control probe or erroneous data in memory The probe may be disconnected burned out or shorted Check that the probe is connected properly The probe may be checked with an ohmmeter to see if it is open or shorted The probe is a thermistor The resistance should read approximately 3 kohms between pins 3 and 4 12 kohms between pins 1 and 4 and 9 11 kohms be tween pins 1 and 3 at room temperature 25 C If the probe appears to be defective contact an Authorized Service Center see Section 1 3 on page 5 for assis tance e f the pr
78. terface In this case the user may set the interface address within the IEEE 488 parameter menu This menu does not appear on baths not fitted with the interface The menu is indicated by IEEE IEEE 488 parameters menu Press SET to enter the menu IEEE 488 Address The IEEE 488 interface must be configured to use the same address as the ex ternal communicating device The address is indicated by Adjust the value with UP or DOWN and then use SET to set the address to the displayed value Rdd 15 New IEEE 486 interface address Calibration Parameters The operator of the bath controller has access to a number of the bath calibra tion constants namely CTO H and L These values are set at the factory and must not be altered The correct values are important to the accuracy and proper and safe operation of the bath Access to these parameters is available to the user only so that in the event that the controller s memory fails the user may restore these values to the factory settings The user should have a list of these constants and their settings with the manual 49 7012 Calibration Bath User s Guide 50 DO NOT change the values of the bath calibration constants from the factory set 9 14 1 9 14 2 values The correct setting of these parameters is important to the safety and proper operation of the bath The calibration parameters menu is indicated by CAL Calibration paramet
79. terface Parameters The 7012 bath may optionally be fitted with an RS 232 interface The serial RS 232 interface parameters menu is indicated by Serial RS 232 interface parameters menu The serial interface parameters menu contains parameters which determine the operation of the serial interface These controls only apply to baths fitted with the serial interface The parameters in the menu are BAUD rate sample pe riod duplex mode and linefeed Baud Rate The baud rate is the first parameter in the menu The baud rate setting deter mines the serial communications transmission rate The baud rate parameter is indicated by BAUd disk Serial baud rate parameter Press SET to choose to set the baud rate The current baud rate value will then be displayed 1200 b Current baud rate The baud rate of the bath serial communications may be programmed to 300 600 1200 or 2400 baud Use UP or DOWN to change the baud rate value e400 b New baud rate Press SET to set the baud rate to the new value or EXIT to abort the opera tion and skip to the next parameter in the menu 47 7012 Calibration Bath User s Guide 48 9 12 2 9 12 3 9 12 4 Sample Period The sample period is the next parameter in the serial interface parameter menu The sample period is the time period in seconds between temperature measure ments transmitted from the serial interface If the sample rate is s
80. the display shows the set point memory that is cur rently being used and its value Eight set point memories are available SET Access set point selection Press SET to accept the new value and display the vernier value The bath be gins heating or cooling to the new set point 4 Quick Start Setting the Temperature SET Store new set point access vernier 0 00000 Current vernier value ex Return to the temperature display Ins Pr A DUE The bath heats or cools until it reaches the new set point temperature Set the heater switch to position HIGH to allow the bath to more quickly reach a higher temperature The HIGH setting may be necessary to reach higher tem peratures and control at high temperatures When setting the set point temperature be careful not to exceed the temperature limit of the bath fluid The over temperature cut out should be correctly set to prevent this from happening See Section 9 8 If operating the bath below 45 C set the COOLING power switch to ON The cooling temperature may require adjustment to provide the proper amount of cooling See Section 8 5 To obtain optimum control stability adjust the proportional band as discussed in Section 9 7 15 5 Installation Bath Environment 5 5 1 5 2 5 3 A A Installation CAUTION READ SECTION 6 ENTITLED BATH USE before placing the bath in service Incorrect handling can damage the bath and void the warranty
81. ting may also be required for control at high tempera tures The LOW setting is used for control at lower temperatures and for scanning at slower rates When controlling at the HIGH heater power setting instead of LOW the proportional band may need to be increased typically by a factor of four to compensate for the increase in power gain Otherwise the temperature may oscillate Cooling The back pressure control valve limits the cooling capacity of the unit It will normally be open all the way full CCW for temperature slewing and opera tion If during operation the front panel meter indicates excessive cooling this valve is closed partially turn CW until the percentage of heating to cooling is brought into line It is necessary to wait a few minutes after each adjustment until the system settles Set the COOLING TEMPERATURE according to the cooling label The cool ing temperature should NOT be set above 90 psig At about 45 C the refrigera tion will not be required as there is sufficient cooling to the room Wait a few minutes after each adjustment until the system establishes itself Readjust if re quired after settling for a while For maximum cooling for slewing to lower temperatures the BACK PRES SURE valve should be fully open and the COOLING TEMPERATURE set to 0 C Readjust higher or lower as required after set temperature is reached Fluid Drain The drain at the back of the bath see Figure 4 and Figure 5
82. tively Refer to Figure 10 for applying the equa tions to the example data and computing the new probe constants 11 Calibration Procedure Calibration Example DO 25 229 DG 186 974 tj 25 00 C measured t 24 869 C ty 75 00 C measured t 74 901 C Compute errors err 24 869 25 00 C 0 131 C erry 74 901 75 00 C 0 099 C Compute DO _ 0 131 75 0 25 229 0 099 25 0 25 229 75 0 25 0 DO 225 229 25392 Compute DG _ 70 099 0 131 75 0 25 0 DG 1 186 974 187 094 Figure 10 Sample calibration computations 61 12 Maintenance 12 Maintenance The calibration instrument has been designed with the utmost care Ease of op eration and simplicity of maintenance have been a central theme in the product development Therefore with proper care the instrument should require very little maintenance Avoid operating the instrument in dirty or dusty environments A battery is used to maintain operating parameters in the unit All operat ing parameters including calibration parameters should be checked on a regular basis to insure accuracy and proper operation of the instrument See the troubleshooting section for the procedure on checking the status of the battery The bath should be cleaned regularly to prevent a buildup of oil or dust Use a paint safe cleaning agent on all painted surfaces Solvents su
83. to coordinate service on your Hart product Fluke Corporation Hart Scientific Division 799 E Utah Valley Drive American Fork UT 84003 9775 USA Phone 1 801 763 1600 Telefax 1 801 763 1010 E mail support hartscientific com 7012 Calibration Bath User s Guide Fluke Nederland B V Customer Support Services Science Park Eindhoven 5108 5692 EC Son NETHERLANDS Phone 31 402 675300 Telefax 31 402 675321 E mail ServiceDesk fluke nl Fluke Int l Corporation Service Center Instrimpex Room 2301 Sciteck Tower 22 Jianguomenwai Dajie Chao Yang District Beijing 100004 PRC CHINA Phone 86 10 6 512 3436 Telefax 86 10 6 512 3437 E mail xingye han fluke com cn Fluke South East Asia Pte Ltd Fluke ASEAN Regional Office Service Center 60 Alexandra Terrace 403 16 The Comtech Lobby D 118502 SINGAPORE Phone 65 6799 5588 Telefax 65 6799 5588 E mail antngOsinga fluke com When contacting these Service Centers for support please have the following information available e Model Number e Serial Number 1 Before You Start Authorized Service Centers e Voltage e Complete description of the problem 2 Introduction Introduction The Hart Scientific 7012 bath is a very precise constant temperature bath An innovative state of the art solid state temperature controller has been incorpo rated which maintains the bath temperature with extreme stability The control ler uses a microcont
84. u mea RUE a ORO SUR NUES RUE we Aca great he 52 10 1 3 Serial Operation co sacia vw E web a a y Yee qos We de 53 10 2 IEEE 488 Communication 53 10 2 1 SETUP ihe Fw Bia Gs eat Blade a Dane a os 53 10 2 1 1 IEEE 488 Interface Address 53 10 2 2 TEEE 488 Operation 2 s swor maei ee es 53 10 3 Interface Commands emo 9 wo Boe we ew 53 10 4 Power Control Functions 56 10 4 1 Heater Control a s Tes sedo Dies eod eh ub E doces eee 56 10 4 2 Cooling Control udo Rx Re etx Dt cete ee IER 56 11 Calibration Procedure 59 11 1 CalibationPoints 59 11 2 Measuring the Set point Error 59 11 3 Computing DO andDG 60 11 4 Calibration Example 60 12 Maintenance 63 12 1 Draining the Bath s s e sk eo des Rok EIER 64 13 Troubleshooting OF 13 1 Troubleshoo ng cR Xe mm RR seas 67 13 2 Comments wx Ey Rd EX CP Y v 70 13 2 1 EMC Directives 2d d aoo OUR aa XOU C ORG dre RR e 70 13 22 Low Voltage Directive Safety gt 70 lii Figures and Tables Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Table 2 Figure 7 Table 3 Figure 8 Figure 9 Table 4 Table 4 Table 5 Table 6 Figure 10 Bath Assembly 4 4406 2046 54 da des ue oov EE 9 Front Panel oz 4404
85. ure limits of the bath fluid could cause harm to the operator lab and instrument e The over temperature cutout should be checked every 6 months to see that it is working properly In order to check the user selected cutout follow the controller directions Section 9 8 for setting the cutout Both the man ual and the auto reset option of the cutout should be checked Set the bath temperature higher than the cutout Check to see if the display flashes cut out and the temperature is decreasing e The constant temperature bath depends upon the certain qualities of the fluid medium in order to maintain a uniform and stable temperature envi ronment Some oils change their characteristics or become dirty after a period of use Always remove any foreign materials from the bath e Silicone oils as well as others may evaporate off their lighter components over a period of time leaving the very viscous components remaining In addition some decomposition occurs which may impair the temperature stability of the bath When this happens the fluid is generally very dark to black and viscous Vegetable oils polymerize turn plastic like after they have been used for a time at high temperatures making them very difficult to remove When the oil has become unusable it should be changed The instructions for removing the oil is as follows 12 1 Draining the Bath The drain is located on the back of the bath See Figure 4 on page 24 Locate the drain plu
86. uw SET SET i SET Po SET z seT X 5 Y i Y 1 Y 2 Y Cutout Hy BAUD Pod Device Do Reset Mode 1 Rate i H Address cro SET EXIT SET EXIT H gt SET EXIT SET EXIT LU SET EXIT NE iu A Adj Cutout i Adjust Adj Device ies 1 I os I 1 I SETEXIT SET EXIT SET EXIT no SET EXIT 2 SET EXIT E iK DG D Sample 1 i gt Period E IEEE 488 i u 1 in d i i SET EXIT gt SET EXIT Option Installed LU ser ies i po eeto metea es me a e esas E CO Re TED H z I SET EXIT 1 SET EXIT 1 lt SETEXT i i Duplex A 2 L Mode O H SET EXIT i Z ser EXIT i i 9 i Adj Duplex gt i SET EXIT i SET EXIT Y Linefeed j SET EXT i Adjust i 1 Linefeed 1 1 1 i SET EXIT i 1 1 i RS 232 i 1 Figure 7 Controller Operation Flowchart 38 Option Installed 9 Controller Operation Temperature Set point 9 3 9 3 1 Cutout reset function Press SET once more to reset the cutout SET Reset cutout This switchs the display to the set temperature function To return to displaying the temperature press the EXIT button If the cutout is still in the over tem perature fault condition the display continues to flash CuE out The bath temperature must drop a few degrees below the cutout set point before the cut out can be reset Temperature Set point The bath temperature can be set to any value within the range and with resolu tion as given in the specifications
87. zed for a dry out period of 1 2 hours before it can be assumed to meet all of the safety requirements of the IEC 1010 1 Bath Preparation and Filling The 7012 Bath is not provided with a fluid Various fluids are available from Hart Scientific and other sources Depending on the desired temperature range any of the following fluids as well as others may be used in the bath 17 7012 Calibration Bath User s Guide 5 4 5 5 e Water e Ethylene Glycol Water e Methanol e Mineral oil e Silicone oil Fluids are discussed in detail in Section 8 1 Remove any access hole cover from the bath and check the tank for foreign matter dirt remnant packing material etc Use clean unpolluted fluid Care fully fill the bath through the large square access hole to a level that will allow for stirring and thermal expansion The fluid should never exceed a height of 1 2 below the top of the tank Carefully monitor the bath fluid level as the bath temperature rises to prevent overflow or splashing Remove excess fluid if nec essary and with caution if the fluid is hot Be careful to prevent bath fluid from spilling on the stirring motor while filling CAUTION Under filling may reduce bath performance and may possibly damage the bath heater Probe Inspect the bath controller probe This probe should not be bent or damaged in any way Reasonable caution should be used in handling this probe as it con tains a precision thermistor

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