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1. 11 1 6 If the display flashes any of the following 11 2 CEComments 11 2 1 EMC Directive 11 2 2 Low Voltage Directive 11 3 Wiring Diagram IV Figures and Tables Table 1 Table 2 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Table 3 Table 3 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 9260 Specifications 2 2 00 eee 3 Mini Cell Specifications 204 4 Bottom Panel 0 0 00004 ee eee 11 Front Panel eS Ss 12 TOO Panel ss 2056 ac lt lt lt a Rees O Q GEES 13 Rear Panel ES 15 Thermal Block Assembly 16 Typical Sealed Mini Fixed Point Cell 18 Comparison Blocks 0 005000 21 Flow Chart ene es E 24 Serial Cable Wiring ooa 37 Communications Command Summary 40 Communications Command Summary cont 41 Melting Point Realization 45 Freezing Point Realization 48 9260 Comparison Block Heating Up 52 9260 Comparison Block Cool Down 52 Wiring Diagram i i fae oe ad dA 61 9260 1 Introduction Introduction The model 9260 is a specialized furnace for the realization of certain defining fixed point
2. 204 5 7 2 Comparison Block Assembly 5 7 2 1 Comparison Block 5 7 2 2 ThermalShunt 5 77 23 Top Insulation lt lt 2 aa E Sh ER E pd Controller Operation 6 1 Well Temperature 6 2 ResetCutl oul __ a aa a 6 3 Temperature Set point 6 3 1 Programmable Set points 00 6 3 2 Set pointValue 0 000 ee eee eee 6 4 Temperature Scale Units 65 SCA 2 0 k s S k k k S k amp k s Q K dad 26 6 5 1 ScanControl 20034 26 6 5 2 Scan Rate sd po e we E e enn Oa we as es na 26 6 6 Program Advance 27 6 7 Temperature Scale Units 27 6 8 Secondary Menu 06 27 6 9 Heater Power 2 5508 27 6 10 Set point Resistance 28 6 11 Proportional Band 4 44 as E ei 2 28 6 12 Controller Configuration 30 6 13 Operating Parameters 30 GAGA High LMt 0 0 4 aa ave ear L s Sl p eee ee wd wd 30 6 13 2 SOnCUPOUL ss se ow wk a sie Ee a ee sls ee we A 30 6 13 3 Cut out Reset Mode 04 31 6 14 Program Parameters 31 6 14 1 Fixed point X a a 31 Gite T ur u 2 u 2 S K S S x SUQ che chee eae ct 32 6 14 3 Curve Temperature _ _
3. ee eee es 32 6 15 Serial Interface Parameters 33 6 15 1 BAUD Rate aoaaa ee dE A 33 6 15 2 Sample Period eee eee 33 6 15 3 Duplex Modes steps 2 eh Boe ee ds DEE E 34 6 15 4 Linefeed a ee ra 34 6 16 Calibration Parameters 34 6 16 1 Hard Cut out 24645 bBo ee eh eee RHE EA dA 35 GADO E E mus E Gee nee es 35 6163 ALPHA 35 6164 DEM oss u s t ss ama E dd Hades W SUR QO oS Q N 35 6 16 5 Top and Bottom Zone Percent Heating 30 6 16 5 1 Bottom Zone css suga ganda oe Ed ss 36 6 16 5 2 TopZone ww oe D4 36 7 Digital Communication Interface 37 7 14 Serial Communications 37 Gl Ms 2242468644225 s 5868 55 x QU S wees 38 Rio C pus ce aa spread Rd ADE dE 38 7 1 2 1 BAUD Rate 38 7 1 2 2 Sample Period 2 2 38 7 1 2 8 Duplex Mode 38 7 1 2 4 Linefeed 39 714 3 SerialOperation 0 0 0000 eee ees 39 7 2 Interface Commands 39 8 Fixed Point Realization 43 8 1 General _ _ a 43 8 2 Installing a Sealed Cell into the Basket 43 8 3 Melting Point Realization 45 8 3 1 Melting Point Procedure 004 46 8 3 1 1 Preparation 2 4
4. A 50 and equilibration FREEZE during plateau VID 4 me Furnace Temperature Controlled Heating Cell Sample Temperature Rate Melting and Freezing Note Have monitor PRT Point Temperature in cell from the Program Advance beginning of procedure User Adjustable 150 250 Time minutes Figure 11 Freezing Point Realization 8 4 1 2 8 4 1 3 monitor thermometer should be inserted into the cell to monitor the process from the beginning Setting Up The Controller Setup of the controller consists of selecting the mode and fixed point to be used The setup is in the secondary menu of the controller menus Access the program parameters by pressing SET and EXIT simultaneously Then press SET 4 times and UP until the program menu is reached The word Prob is displayed Press SET FP fixed point flashes and then the cur rent setting is displayed The metal sample displayed is from the previous test Press UP or DOWN repeatedly to toggle through Indium Tin Zinc Aluminum and Other When you reach the desired fixed point press SET to select the metal sample to use Immediately after pressing SET CURVE flashes and the current setting nELt or Fr EE ZE appears The terms indi cate the first of the two curves melt or freeze Use the UP or DOWN key to view the desired curve F EE z E Press SET to select this curv
5. ing 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 150 0 will set the set point to 150 0 degrees In the following list of commands characters or data within brackets and 4 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 ig nored Backspace BS ASCII 8 may be used to erase the previous character A terminating CR is implied with all commands 9260 Manual Rev 970701 39 7 Digital Communication Interface Table 3 Communications Command Summary Command Command Returned Acceptable Command Description Format Example Returned Example Values Display Temperature Read units u u u C or F u C Read current set point s etpoint S set 9999 99 C or F set 150 00 C Set current set point to n s etpoint n s 450 Instrument Range Read temperature t t t 9999 99 C or F t 478 03 C 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 Read scan function sc an sc scan ON or OFF sca
6. 106kPa e mains voltage within 10 of nominal e vibrations in the calibration environment should be minimized e altitude does not effect the performance or safety of the unit 2 3 Warranty Hart Scientific Inc Hart warrants this product to be free from defects in ma terial and workmanship under normal use and service for a period as stated in our current product catalog from the date of shipment This warranty extends only to the original purchaser and shall not apply to any product which in Hart s sole opinion has been subject to misuse alteration abuse or abnormal conditions of operation or handling Software is warranted to operate in accordance with its programmed instruc tions on appropriate Hart products It is not warranted to be error free Hart s obligation under this warranty is limited to repair or replacement of a product which is returned to Hart within the warranty period and is determined upon examination by Hart to be defective If Hart determines that the defect or malfunction has been caused by misuse alteration abuse or abnormal condi tions or operation or handling Hart will repair the product and bill the pur chaser for the reasonable cost of repair Manual Rev 970701 Hart Scientific 9260 2 Specifications and Environmental Conditions To exercise this warranty the purchaser must forward the product after calling or writing Hart for authorization Hart assumes NO risk for in transit damage
7. 6 Controller Operation Display Temperature Reset Cutout Cutout Active Select Setpoint Adjust Setpoint Units C F Scan On Off Operating Parameters Menu Soft Cut out Cut out Reset Mode Adj Cut out Reset Select Fixed Point Configuration Menu Program Serial UP Parameters DOWN Interface DOWN Menu Menu SET Fixed Point BAUD Rate Curve Set point Adj Curve Set point SET Down Menu Legend Press SET to step through the menu and to store the parameter value Press EXIT briefly to skip a parameter without storing the parameter value Select Program Advance Hold EXIT to exit the menu and display the temperature Secondary Functions ser Display Power Set Set Point Resistance Set Proportional Band Adjust BAUD Rate TWANVIN 33S SAN TVA 3S3H1 ADNVHO LON OG Sample Period Adj Sample Period Adj DELTA Bottom Zone Adjust Bottom Zone Adjust Top Zone Duplex Mode Adj Duplex Mode Linefeed DO NOT CHANGE THESE VALUES SEE MANUAL Adjust Linefeed Figure 8 Flow Chart 24 Manual Rev 970701 Hart Scientific 6 Controller Operation Press SET once more to reset the cut out ser Reset cut out This will also switch the display to the set temperature function To return to displaying
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9. For service or assistance please contact Hart Hart Scientific Inc 799 East Utah Valley Drive American Fork UT 84003 9775 Phone 801 763 1600 Fax 801 763 1010 E mail support hartscientific com THE FOREGOING WARRANTY IS PURCHASER S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OR MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR USE HART SHALL NOT BE LIABLE FOR ANY SPECIAL INDIRECT IN CIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSS WHETHER IN CONTRACT TORT OR OTHERWISE Manual Rev 970701 5 9260 3 Safety Guidelines 3 Safety Guidelines Operate the instrument in room temperatures between 5 45 C 41 113 F Allow sufficient air circulation by leaving at least 6 inches of space between the furnace and nearby objects Overhead clearance needs to allow for safe and easy insertion and removal of probes for cali bration The furnace is a precision instrument Although it has been designed for optimum durability and trouble free operation it must be handled with care Always carry the unit in an upright position to prevent the comparison blocks from falling out Keep the well of the instrument clean and clear of any foreign matter Do not operate near flammable materials Do not use fluids to clean out the well Do not move the furnace with the fixed point cells inside They can be eas ily broken The instrument c
10. However actual heat losses will vary with the design of the ther 50 Manual Rev 970701 Hart Scientific 8 Fixed Point Realization mometer probes inserted into the instrument and the temperature For best re sults insert the probe to the full depth of the well DO NOT heat the thermometer hub or handle above the rated temperature 8 5 2 1 Stabilization and Accuracy The stabilization time of the instrument depends on the conditions and temper atures involved Typically the test well will be stable to 0 1 C within 10 minutes of reaching the set point temperature as indicated by the display Ultimate sta bility will be achieved 15 to 20 minutes after reaching the set temperature In serting a cold probe into the well requires another period of stabilization depending on the magnitude of the disturbance and the required accuracy For example inserting a 0 25 inch diameter room temperature probe into a com parison block at 300 C takes 5 minutes to be within 0 1 C of its settled point and takes 10 minutes to achieve maximum stability Speeding up the calibration process can be accomplished by knowing how soon to make the measurement Test measurements should be made at the desired temperatures with the desired test probes to establish these times 9260 Manual Rev 970701 51 8 Fixed Point Realization Temperature C 0 15 30 45 60 75 Time minutes Figure 12 9260 Comparison Block Heating Up Temperature C 0 3
11. instrument Ifthe comparison block is dropped examine the comparison block for de formities before inserting it in the well If there is any chance of jamming the comparison block in the well file or grind off the protuberance Do not slam the probe stems into the well This type of action can cause a shock to the sensor or break the entrant well of a fixed point cell lf a hazardous material is spilt on or inside the equipment the user is re sponsible for taking the appropriate decontamination steps as out lined by the national safety council with respect to the material If the mains supply cord becomes damaged replace it with a cord with the appropriate gauge wire for the current of the instrument If there are any questions call Hart Scientific Customer Service for more information Before using any cleaning or decontamination method except those rec ommended by Hart users should check with Hart Scientific Customer Ser vice to be sure that the proposed method will not damage the equipment If the instrument is used in a manner not in accordance with the equipment design the operation of the furnace may be impaired or safety hazards may arise Manual Rev 970701 57 11 Troubleshooting 11 Troubleshooting If problems arise while operating the 9260 this section provides some sugges tions that may help you solve the problem A wiring diagram is also included 11 1 Troubleshooting Below are several situations that ma
12. which the unit was tested 11 2 2 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 IEC 1010 2 010 EN 61010 2 010 standards Manual Rev 970701 Hart Scientific 11 Troubleshooting 11 3 Wiring Diagram L db iaaHS 3NON avos asvaisy SUIYO DEL A0ZZ 104 SWUO Z ASLL 104 y ZEMZ LZ0D L rF9F9 j YJJNI9NI
13. 6 9 12 15 18 Time hours Figure 13 9260 Comparison Block Cool Down 52 Manual Rev 970701 Hart Scientific 9 Furnace Calibration 9 Furnace Calibration For optimum performance in realizing melting or freezing points of fixed point cells calibration of the 9260 must be maintained Excessive temperature gra dients and inaccurate furnace temperatures can make it difficult to realize melting or freezing points reduce the length of the melting or freezing plateau and even possibly damage a fixed point cell For best results the vertical tem perature uniformity should be kept within 0 2 C over the lower 12 cm 5 in and the temperature accuracy should be kept within 0 5 C The temperature profile and accuracy should be checked often and adjusted as necessary While the furnace is new consider checking these at least once a month The following sections explain the temperature profile and temperature accuracy calibration procedures 9 1 Temperature Profile Adjustment The 9260 Furnace is adjusted at the factory for a flat vertical temperature pro file The temperature profile should be regularly checked and adjusted as nec essary to maintain it within about 0 2 C over the bottom 12 cm 5 in witha slightly higher temperature toward the top The following steps explain how to test and adjust the temperature profile The temperature accuracy should sub sequently be calibrated according to Section 9 2 below whenever the zones are ad
14. a alpha FAR F a Fa Delta is the new value of DELTA computed above Program the new values for DELTA delta RO rzero and ALPHA alpha into the furnace by pressing the SET and EXIT keys simultaneously and then pressing SET until RO is displayed Press SET then use the UP or DOWN keys until the correct numerical setting is displayed Press SET to accept the new value Continue this process for ALPHA and DELTA 9 2 5 Accuracy and Repeatability Check the accuracy of the furnace at various points over the calibrated range If the furnace does not pass specification at all set points repeat the Calibra tion Procedure Manual Rev 970701 Hart Scientific 9260 10 Maintenance 10 Maintenance The calibration instrument has been designed with the utmost care Ease of operation 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 an oily wet dirty or dusty environment Ifthe outside of the instrument becomes soiled it may be wiped clean with a damp cloth and mild detergent Do not use harsh chemicals on the sur face which may damage the paint It is importantto keep the well ofthe instrument clean and clear of any for eign matter Do not use fluid to clean out the well The furnace should be handled with care Avoid knocking or dropping the
15. a special aluminum bronze alloy that is resistant to the temperatures that the furnace is capable of reaching Heaters surround the cell in order to provide uniform heat The 9260 fea tures adjustable top and bottom zone heaters that help to keep the temper ature uniform over the entire fixed point cell These zone heaters add heat to each end of the block where more heat is lost to ambient Inner Melt Heater Cooling Air Vents Pre Heat Wells Constant Temperature Block Assembly Figure 3 Top Panel 9260 Manual Rev 970701 13 14 5 Parts and Controls 5 4 5 5 5 5 1 A high temperature platinum resistance thermometer is imbedded into the wall of the block to sense and control the temperature of the block This en tire assembly is insulated and suspended in the airflow of the fan to remove lost heat and to keep the chassis cool The thermometer pre heat wells are located on either side of the block ac cess well Thermometers are pre heated in these wells prior to insertion into the cell in order to conserve its latent energy The inner melt heater is a low power heater that creates an inner liquid layer next to the reentrant tube of the fixed point cell during the melting curve process This inner melt heater is controlled automatically by the mi croprocessor when using the program mode or may be used manually with the switch in back When not in use the inner melt heater is stored in the well at the back of t
16. calibrator the calibration of the controller provides the reference temperature As a comparator a reference thermometer value is compared to the values of the units under test A smaller uncertainty is obtainable with the comparison method Comparison blocks are available as options to the furnace Block Well Sizes Three standard comparison blocks are available See Figure 7 Model 3160 2 provides 9 wells with clearance for 1 4 inch diameter thermometers Model 3160 3 is a combination of wells providing access for a variety of popu lar sizes Model 3160 1 is a blank block that can be drilled by the user to any desired sizes Comparison Block Assembly Comparison blocks provide a uniform temperature between multiple thermom eters For accurate results the thermometers must fit closely inside the well The comparison block assembly is comprised of three components the com parison block the thermal shunt and the top insulation Comparison Block The comparison block is carefully lowered to the bottom of the thermal block well with the tongs provided DO NOT drop the block into the well Damage to the furnace may result Small changes to the furnace calibration may result as well Thermal Shunt Just above the comparison block is a ledge in the thermal block itself The thermal shunt is lowered into the thermal well until it rests on this ledge The insertion wells must match the comparison block This block conducts heat from the t
17. set point tem perature The control buttons SET DOWN UP and EXIT are used to set the instrument temperature set point access and set other operating pa rameters and access and set calibration parameters Setting the control temperature is done directly in degrees of the current scale and can be set to 0 01 of a degree Celsius or Fahrenheit The functions of the buttons are as follows SET Used to display the next parameter in the menu and to store parameters to the displayed value DOWN Used to decrement the displayed value of parameters UP Used to increment the displayed value EXIT Used to exit a function and to skip to the next function Any changes made to the displayed value are ignored Holding EXIT for about 1 2 a sec ond returns control to the main display SET DOWN UP EXIT ADV eas Figure 2 Front Panel 12 Manual Rev 970701 Hart Scientific 5 Parts and Controls 5 3 Top Panel The primary feature of the top of the unit is the access to the tempera ture controlled block The top panel consists of the constant temperature block assembly the pre heat wells the inner melt heater and cooling air vents See Figure 3 1 The constant temperature block assembly is where the cell basket contain ing the fixed point cell is inserted Or when the furnace is used as a temper ature comparator where the pre drilled inserts are placed for inserting the thermometers The block assembly is made of
18. the UP and DOWN keys and then pressing SET See Figure 8 on page 24 6 13 Operating Parameters Press SET to enter the menu The operating parameters menu contains the High Limit HL parameter the Soft Cut out parameter and the Cut out Reset mode parameter 6 13 1 High Limit The High Limit parameter adjusts the upper set point temperature The factory default and maximum are set to 680 C For safety a user can adjust the High Limit parameter down so the maximum temperature set point is restricted eee ting Press SET to accept the new High Limit parameter and to access the Soft Cut out parameter 6 13 2 Soft Cut out The next parameter in this menu is the Soft Cut out The Soft Cut out parame ter is used by the controller to shut down the unit during over temperature con ditions If the temperature of the unit is ever greater than the Soft Cut out temperature the controller shuts itself down and displays alternately SCeGut and Err B O Manual Rev 891101 Hart Scientific 6 Controller Operation Press SET to accept the new parameter and to access the Cut out Reset Mode 6 13 3 Cut out Reset Mode The final parameter in this menu is the Cut out Reset Mode The Cut out Re set Mode determines whether the cut out resets automatically when the well Empate drops to a safe value or must be manually reset by the operator CkEor SE Flashes Ck or St Cut out reset
19. the temperature press the EXIT button If the cut out is still in the over temperature fault condition the display will continue to flash cut out The well temperature must drop a few degrees below the cut out set point before the cut out can be reset 63 Temperature Set point The temperature set point can be set to any value within the range and resolu tion as given in the specifications Be careful not to exceed the safe upper temperature limit of any device inserted into the well Setting the temperature involves selecting one of the eight 8 set points in memory and then adjusting the set point value 6 3 1 Programmable Set points The controller stores eight 8 set point temperatures in memory The set points can be quickly recalled to conveniently set the instrument to a previ ously programmed temperature set point To set the temperature first select the set point memory This function is ac cessed 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 DOWN Press SET to accept the new selection and access the set point value ser Accept selected set point memory Note Pressing SET at this point turns off the program mode if it is on 6 3 2 Set point Value The set point value may be adjusted after selecting the set point memory and 9260 Manual Re
20. thermal shunt over the top of the basket fitting it onto the ledge above Check the alignment Fit the top insulation above the shunt Carefully check the thermometer fit all the way to the bottom of the cell There must not be any significant resistance to insertion Place a small pad of quartz wool at the bottom of the reentrant well of the cell which will to some extent pad the bottom of the well against the ther mometers when they are inserted CAUTION Careless insertion of a thermometer into the well can break the quariz glass at the bottom or even break quartz thermometers Manual Rev 970701 Hart Scientific 8 Fixed Point Realization CAUTION Occasionally remove the thermal shunt and the basket If there is any resistance to removal remove oxides with fine grit sandpaper This is generally only a problem at the aluminum point 8 3 Melting Point Realization Recent improvements of the melting point method have shown that excellent accuracy can also be achieved with this method With this method the cell temperature is carefully raised to a temperature just below the melting point The furnace and cell are allowed to dwell at this temperature for a time to al low temperature equalization throughout the system The furnace is then raised to a point a few degrees above the melting point for a short time to give melting a good start The temperature is then dropped to a temperature just above the melting point for the durati
21. 0 and the version of the software The unit will need to be repro grammed for RO ALPHA and DELTA in the calibration menu These num bers can be found on the Report of Calibration that was shipped with the unit 9260 Manual Rev 970701 59 11 Troubleshooting 11 1 5 11 1 6 11 2 11 2 1 If the display flashes any of the following err 6 This error means there is a SENSOR error e Thesensor is disconnected or shorted Please contact Hart Scientific Cus tomer Support for further instructions If the display flashes any of the following err 7 This error means there is a HtrCTL error The fan will go on high speed Initialize the system by performing the master reset sequence If the unit repeats the error code turn the unit off and contact Hart Scientific Customer Support for a return authorization and for instructions on returning the unit CE Comments EMC Directive Hart Scientific s equipment has been tested to meet the European Electromag netic Compatibility Directive EMC Directive 89 336 EEC Selection of Light Industrial or Heavy Industrial compliance has been based on the intended use of the instrument Units designed for use in a calibration laboratory have been tested to Light Industrial Standards Units designed to be used in the field have been tested to both Light Industrial and Heavy Industrial Standards The Declaration of Conformity for your instrument lists the specific standards to
22. 0 to 200 per cent Manual Rev 970701 Hart Scientific 7 Digital Communication Interface 7 Digital Communication Interface The furnace is capable of communicating with and being controlled by other equipment through the digital serial interface With a digital interface the instrument may be connected to a computer or other equipment This allows the user to set the set point temperature monitor the temperature and access any of the other controller functions all using re mote communications equipment Communications commands are summa rized in Table 3 on page 40 7 1 Serial Communications The instrument is installed with an RS 232 serial interface that allows serial digital communications over fairly long distances With the serial interface the user may access any of the functions parameters and settings discussed in Section 6 with the exception of the BAUD rate setting RS 232 Cable Wiring for IBM PC and Compatibles Instrument Computer DTE Connector Connector DB 9 Pin DB 9 Pin INC 1 DCD 2 RxD e e 2 RxD 3TxD 3TxD 4NC e 4 DTR 5 GND 5 GND 6NC e 6 DSR 7 RTS TT 7 RTS 8CTS 8 CTS 9NC 9 NC Instrument Computer DTE Connector Connector DB 9 Pin DB 25 Pin 1NC e 2 RxD 2TxD 3TxD e e 3 RxD 4NC e 4RTS 5 GND e 5 CTS 6NC e 6 DSR 7RTS e e 7 GND 8 CTS 8 DTD 9NC e 20 DTR Figure 9 Serial Cable Wiring 9260 Manual
23. 2 13 14 15 16 17 Install the cell pad into the bottom of the basket Typically a 1 4 6 85 mm thick pad is used It will crush to a thinner dimension as the cell is installed It SHOULD NOT be so thick that the basket cover touches the cell at the top If the pad contains an organic binder heat the pad to remove it before use Cut a strip of clean paper approximately 1 inch wide and 1 inch longer than the basket Insert this paper into the bottom of the basket while it is lying down At least 1 inch of the paper should be extending out of the basket for easy removal Temporarily hold the sealed cell sideways with the spherical end toward the basket opening Carefully insert the cell into the basket sliding it on the paper instead of on the metal basket When the cell reaches the bottom return the basket care fully to the upright position Remove the paper completely Install a thin insulating pad on top of the cell providing a clearance hole for the thermometer Check the basket cover fit to ensure that the evacuation port on the top of the cell does not prevent it from fitting flush against the top of the basket Remove the lid for now Using the tool provided carefully lower the basket into the thermal well Install the basket lid on top of the basket being sure that it is flush against the basket Install a thin insulation pad on top of the lid with a clearance hole for the thermometer Install the
24. 31 er CUVOS TIONLNOO TVLIDIA alva VAO dddV Aq NOI 1dl 3OS3dq YLT SNOISIASY Manual Rev 970701 Figure 14 Wiring Diagram 9260
25. 4 Linefeed The final parameter in the serial interface menu is the linefeed mode This pa rameter enables 8 n or disables 0 F F transmission of a linefeed character LF 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 7 1 3 Serial Operation Once the cable has been attached and the interface set up properly the con troller immediately begins transmitting temperature readings at the pro grammed rate The serial communications uses 8 data bits one stop bit and no parity The set point and other commands may be sent via the serial inter face to set the temperature set point and view or program the various parame ters The interface commands are discussed in Section 7 2 All commands are ASCII character strings terminated with a carriage return character CR ASCII 13 7 2 Interface Commands The various commands for accessing the instrument functions via the digital interface are listed in this section see Table 3 These commands are used with the RS 232 serial interface The commands are terminated with a car riage return character The interface makes no distinction between upper and lower case letters hence either may be used Commands may be abbreviated to the minimum number of letters that determines a unique command A com mand may be used to either set a parameter or display a parameter depend
26. 4668 2 mad DE SE O 46 8 3 1 2 Setting Up The Controller 46 8 3 1 3 Program Initiation 05 46 8 4 Freezing Point Realization 47 9 8 4 1 Freezing Point Procedure 0 8 4 1 1 Preparation 2 6 44 6 eee ee as eS 8 4 1 2 Setting Up The Controller 8 4 1 3 Program Initiation 20 8 5 Test Probe Calibration 8 5 1 Calibrating a Single Probe 8 5 2 Furnace Characteristics 0 004 8 5 2 1 Stabilization and Accuracy Furnace Calibration 9 1 Temperature Profile Adjustment 9 1 1 Step 1 Measure the profile 9 1 2 Step 2 Adjust the endzones 9 1 3 Repeat Step 1 and Step 2ifnecessary 9 2 Temperature Calibration 9 2 1 One point Calibration 2 0 0 2 9 2 2 Three point Calibration 0 00008 9 2 3 Compute DELTA 9 2 4 Computer RO and Alpha 0 a 9 2 5 Accuracy and Repeatability 10 Maintenance 11 Troubleshooting 11 1 Troubleshooting 11 1 1 Incorrect Temperature Reading 11 1 2 The unit will not heat or heats athalfrate 11 1 3 The unit heats slowly 11 1 4 Ifthe display flashes any of the following 11 1 5 If the display flashes any of the following
27. 9260 MINI FIXED POINT CELL FURNACE USERS MANUAL HART SCIENTIFIC C Rev 970701 Copyright 1999 All Rights Reserved Hart Scientific 799 E Utah Valley Drive American Fork Utah 84003 9775 Telephone 801 763 1600 Fax 801 763 1010 Internet htto www hartscientific com WARNING To ensure the safety of operating personnel and to avoid damage to this equipment DO NOT operate this unit without a properly grounded properly polarized power cord DO NOT connect this unit to a non grounded non polarized outlet DO USE a ground fault interrupt device WARNING HIGH VOLTAGE is used in the operation of this equipment SEVERE INJURY OR DEATH may result if personnel fail to observe safety precautions Before working inside the equipment turn power off and disconnect power cord WARNING HIGH TEMPERATURES PRESENT in this equipment FIRES AND SEVERE BURNS may result if personnel fail to observe safety precautions gt WARNING To ensure the safety of personnel and to avoid damage to equipment DO NOT use this unit for any application other than calibration work DO NOT use this unit in environments other than those listed in the user s manual Continuous use of this equipment at high temperatures for extended periods of time requires caution Completely unattended high temperature operation is not recommended for safety reasons Components and heater lifetimes can be shorten
28. IT in side indicates the panel button while the dotted box indicates the display read ing Explanation of the button or display reading are to the right of each button or display value Well Temperature The digital LED display on the front panel allows direct viewing of the actual well temperature This temperature value is normally shown on the display The units C or F of the temperature value are displayed at the right For ex ample The temperature display function may be accessed from any other function by pressing the EXIT button Reset Cut out Ifthe over temperature cut out has been triggered then the temperature dis The message continues to flash until the temperature is reduced and the cut out is reset The cut out has two modes automatic reset and manual re set The mode determines how the cut out is reset which allows the instrument to heat up again When in automatic mode the cut out will reset itself as soon as the temperature is lowered below the cut out set point With manual reset mode the cut out must be reset by the operator after the temperature falls be low the set point When the cut out is active and the cut out mode is set to manual reset then the display will flash cut out until the user resets the cut out To access the reset cut out function press the SET button ser Access cut out reset function The display will indicate the reset function Manual Rev 970701 23
29. Rev 970701 37 7 1 1 7 1 2 7 1 2 1 7 1 2 2 7 1 2 3 7 Digital Communication Interface Wiring The serial communications cable attaches to the instrument through the DB 9 connector at the back of the instrument Figure 9 shows the pin out of this con nector and suggested cable wiring To eliminate noise the serial cable should be shielded with low resistance between the connector DB 9 and the shield If the unit is used in a heavy industrial setting the serial cable must be limited to ONE METER in length Setup Before operation the serial interface must first be set up by programming the BAUD rate and other configuration parameters These parameters are pro grammed 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 P A Press UP until the serial interface menu is indicated with SE iAL Finally press SET to enter the serial parameter menu In the serial interface parameters 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 b RU g Press SET to choose to set the BAUD rate The current BAUD rate value will then be displayed The BAUD rate of the 9260 serial commu
30. T or FREEZE Read curve temperatures psn ps3 psn 999 99 C or F ps1 480 00 C Manual Rev 970701 Hart Scientific Communications Command Summary cont 7 Digital Communication Interface Command Command Returned Acceptable Command Description Format Example Returned Example Values Set curve temperatures psn n ps3 100 1 to 3 dependent on program control Serial Interface Menu Read serial sample setting sa mple sa sa 9 sa 1 Set serial sampling setting to n sa mple n sa 0 0 to 4000 seconds Set serial duplex mode du plex f ull h alf FULL 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 If eed on of f ON or OFF Set serial linefeed mode to on lf eed on lf on Set serial linefeed mode to off lf eed of f lf of Cal Menu Read R calibration parameter r 0 r r0 999 999 r0 100 7 Set R calibration parameter to n r 0 n r 100 7 98 0 to 104 9 Read Alpha calibration parameter al pha al al 9 999999 al 0 003865 Set Alpha calibration parameter to n al phal n al 0 003865 002 to 006 Read Delta calibration parameter dellta de de 9 99 de 1 50 Set Delta calibration parameter dellta n de 1 37 Oto 3 Read top zone heating tpct tpct tpct 999 9 tpct 200 0 Set top zone heating tpct n tpct 100 O to 200 Read bottom zone heating bpct bpct bpct 999 9 bpct 150 0 Set bottom zo
31. a main supply power fluctuation occurs immediately turn off the instru ment Power bumps from brown outs and black outs can damage the in strument Wait until the power has stabilized before re energizing the instrument Manual Rev 970701 7 9260 4 Quick Start 4 Quick Start Unpacking Unpack the instrument carefully and inspect it for any damage that may have occurred during shipment If there is shipping damage notify the carrier imme diately Verify that the following components are present e 9260 Furnace e Inner Melt Heater e Power Cord e Manual e Comparison Blocks optional e Cell Basket e Cell Basket Lid e Basket Removal Tool e Thermal Shunt e Top Insulation e Cell Pad Insulation Setup Place the furnace on a flat surface with at least 6 inches of free space around and 18 inches above the instrument Install the power cord into the power en try module on the underside of the furnace Plug the power cord into a grounded mains outlet Verify that the nominal voltage corresponds to that in dicated on the back of the instrument Carefully insert the comparison blocks or cell baskets into the well DO NOT drop them into the well Comparison block holes should be of the smallest di ameter possible while still allowing the probe to slide in and out easily Various hole sizes are available from Hart Scientific The well must be clear of any for eign objects dirt and grit before the comparison block is inse
32. ace has reached that temperature about 1 C below the melting point it dwells there for 60 minutes to permit the furnace and metal sample to equilibrate After the 60 minute pe riod the display flashes on and off alternately indicating that the cell is now ready to initiate the melt function To initiate the melting of the sample press SET and DOWN again Press the UP or DOWN keys until the term MELt is on the display Press SET to select that step and the controller selects a set point temperature a few de 46 Manual Rev 970701 Hart Scientific 8 Fixed Point Realization grees above the melting point to begin the sample melting process The tem perature of the furnace slowly scans to about 4 C above the melting point and dwells there for about 8 minutes At that time the melt heater turns on auto matically This heater melts a thin layer of the sample next to the measure ment thermometer increasing the accuracy of this technique After a few minutes the melt heater automatically turns off and the furnace temperature drops to a temperature just above the melting point of the sample Remove the melt heater and insert a pre heated monitor thermometer When the tempera ture has stabilized calibrations may begin Use the pre heat wells to heat up the thermometers before inserting them into the cell This action preserves the latent energy and permits more calibrations during the melting plateau Allow th
33. an generate extreme temperatures Precautions must be taken to prevent personal injury or damage to objects Probes may be ex tremely hot when removed from the instrument Cautiously handle probes to prevent personal injury Always use the special comparison block tongs that are supplied with the furnace to remove the comparison block or cell basket Carefully place probes on a heat resistant surface or rack until they are at room temperature Never place any objects other than the compari son blocks cell basket or cells supplied with the furnace into the well Use only grounded AC mains supply of the appropriate voltage to power the instrument The furnace requires 11 amps maximum at 115 VAC 10 60 Hz and 6 amps maximum at 230VAC 410 50 Hz Before initial use after transport and anytime the instrument has not been energized for more than 7 days the instrument needs to be energized 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 The instrument is equipped with operator accessible system fuses If a fuse blows it may be due to a power surge or failure of a component Re place the fuse once If the fuse blows a second time it is likely caused by failure of a component If this occurs contact Hart Scientific Customer Service Always replace the fuse with one of the same rating voltage and type Never replace the fuse with one of a higher current rating If
34. asket helps to cushion the cell from the metal bottom Thermal Shunt A disk of aluminum bronze in the top of the thermal well above the basket pro vides heat transfer across the top of the cell and to the thermometer itself The effectiveness of the heat transfer to the thermometer is dependent on its fit to the shunt Measurements at the aluminum point may be affected by heat con ducted up the thermometer stem Insulation The entire block assembly is surrounded by fiber ceramic insulation A remov able portion above the cell permits the cell to be inserted and removed Temperature Control Sensor The temperature control sensor is a high quality PRT with 4 leads Accuracy is calibrated into the unit Zero resistance alpha and delta coefficients of the Calendar Van Dusen equation permit linearization over the desired tempera ture range Mini Fixed point Cells Mini Fixed point Cells Figure 6 utilize physical properties of a substance to provide well established temperatures The sample in the cell is placed into a condition of multiple phases at a melting or freezing temperature or at a tri ple point temperature While the sample substances are in this condition they can exhibit very stable constant temperatures for long periods of time Properly used the temperatures provided by these constants of nature are ex tremely precise and repeatable The International Temperature Scale of 1990 Manual Rev 970701 17 5 Parts and Cont
35. ay followed by adjustments that can be made by the user to the MELT FREEZE and MAINTAIN temperatures These adjustments are only for experienced users Press EXIT to exit the program menu and to return to the display temperature Carefully insert the melt heater into the cell see Figure 3 Set the heater switch on the rear of the furnace to AUTO The heater must be clean and carefully inserted into the cell to prevent damage This should be done before program initiation 8 3 1 3 Program Initiation Now that the fixed point and the melt curve have been selected the furnace is ready to initiate the program Advance to the program from the display temper ature by pressing SET and DOWN The term st P appears unless the program is running The following three steps include MELE mAInt and FrEEZE The step that first appears will be the last step utilized and not nec essarily the first step desired Press the UP or DOWN keys to view the first step needed which is fi Aint for the preliminary heating of the cell to just be low the melting point The cell is held at that temperature for a period of time to allow everything to equilibrate to that temperature Press SET to select it The controller immediately starts heating the cell with its metal sample The furnace heats at a preprogrammed rate that automatically slows down before the sample reaches the fAi NT point Once the furn
36. bout 20 minutes after in serting the SPRT and make careful and accurate measurements Once the temperatures are obtained new values for RO ALPHA and DELTA can be calculated The procedure is summarized as follows 1 Choose three set points to use in the calibration of the RO ALPHA and DELTA parameters These set points are generally 50 C 400 C and 650 C but other set points may be used if desired or necessary 2 Setthe furnace to the low set point When the furnace reaches the set point and the display is stable wait approximately 15 minutes and then take a reading from the thermometer Sample the set point resistance Write these values down as T and R respectively 3 Repeat step 2 for the other two set points recording them as T R T and R respectively 4 Using the recorded data calculate new values for the RO ALPHA and DELTA parameters using the equations given below 9260 Manual Rev 970701 55 9 Furnace Calibration 9 2 3 Compute DELTA T are the measured temperatures using the thermometer R are the val ues of R from the display of the 9260 Press SET and DOWN at the same time T and R are the measured temperature and resistance at 50 C T and R are the measured temperature and resistance at 400 C T and R are the measured temperature and resistance at 650 C 9 2 4 Computer RO and Alpha a T deta 7 A 100 100 Ay la dena Te a 100 100 zero 8 F a
37. detail how to set the temperature set point on the fur nace using the front panel keys The procedure is summarized here 1 Press SET twice to access the set point value 2 Press UP or DOWN to change the set point value 3 Press SET to program in the new set point 4 Press EXIT to return to the temperature display When the set point temperature is changed the controller will switch the well heater on or off to raise or lower the temperature The displayed well tempera ture will gradually change until it reaches the set point temperature The well may require 10 to 75 minutes to reach the set point depending on the span and the scan rate Another 15 minutes is required to stabilize within 0 1 C of the set point Ultimate stability may take 15 to 20 minutes of stabilization time 4 6 Changing Display Units The instrument can display temperature in Celsius or Fahrenheit The instru ment is shipped from the factory set to Celsius To change to Fahrenheit or back to Celsius there are two ways Press SET and UP simultaneously This will change the display units or Press the SET key three times from the temperature display to show Press SET to store changes 10 Manual Rev 970701 Hart Scientific 5 Parts and Controls 5 Parts and Controls The user should become familiar with the 9260 furnace parts Successful use of the instrument is dependent upon knowledge of impo
38. djusted by altering the calibration parameters EoPPCE and bot PCE in the controller see Section 6 16 5 Increasing or decreasing the top zone heat by 1 typically increases or decreases t3 rela 9260 Manual Rev 891101 53 9 Furnace Calibration 9 1 3 9 2 9 2 1 topPct 91 25 botPct 94 25 tive to t by about 0 1 C at 660 C and increases or decreases t relative to t by about 0 03 C Likewise increasing or decreasing the bottom zone heat by 1 typically increases or decreases temperature t relative to t by about 0 1 C at 660 C and increases or decreases temperature t relative to t by about 0 03 C From these relationships the following formulas are derived and these can be used to determine new settings for the top and bottom zones to produce a llat gradient with the top only 0 1 C hotter than the bottom Je t 75 topPct topPct 25 Je t 175 Vo C botPct botPct 25 Je t 75 ds C C Je t 0 75 For example t is measured in Step 1 to be 657 71 t is measured to be 657 83 and t is measured to be 658 41 The bottom zone is set at 94 and the top zone is set at 91 The new settings are calculated as follows Yo Jieszs c 657 71 C 7 5 esearec 657 71 C 175 84 65783 c 657 71 C 75 Jossarc 657 71 C 0 75 93 Repeat Step 1 and Step 2 if necessary Aft
39. e s multiple fault protection de vices insure user and instrument safety and protection The 9260 furnace was designed for high accuracy calibrations using compari son measurements or fixed point calibration methods and for ease of opera tion Through proper use the instrument will continuously provide accurate calibration of temperature sensors and devices The user should be familiar with the safety guidelines and operating procedures of the furnace as de scribed in this user manual Manual Rev 970701 1 9260 2 Specifications and Environmental Conditions 2 Specifications and Environmental Conditions 2 1 Specifications The 9260 specifications are detailed in Table 1 and the Mini Cell specifications are detailed in Table 2 Table 1 9260 Specifications Operating Range 50 C to 680 C 122 F to 1256 F Ambient Temperature 5 C to 45 C 41 F to 113 F Accuracy 0 2 C 50 C to 300 C 0 3 C 300 C to 450 C 0 5 C 450 C to 680 C Stability 0 03 C to 300 C 0 05 C above 300 C Well to Well Gradient 0 02 C 0 036 F Melting Freezing Point Duration 6 to 10 hours typical Vertical Gradients Top and bottom zones adjustable by offset Resolution 0 01 C or F Display Scale C or F switchable Comparison Block Blank block two multi hole blocks and custom blocks available Fault Protection Sensor burnout and short protect
40. e Press EXIT to exit the program menu and to return to the display temperature Program Initiation Now that the fixed point and the freeze curve have been selected the furnace is ready to initiate the program Advance to the program from the display tem perature by pressing SET and DOWN One of three steps of the selected program curve or St OP is displayed The three steps include MELE MAInk Manual Rev 970701 Hart Scientific 8 Fixed Point Realization and Fr EE ZE The step that first appears will be the last step utilized and not necessarily the first step desired Press the UP or DOWN keys to view the first step needed which is mn ELE for the freezing process Press SET to se lect it Note Select stop to turn off the program function Manually adjusting the set point also stops the program The controller immediately starts heating the cell The furnace heats at a preprogrammed rate that automatically slows down before the sample reaches the melting point Once the furnace has reached the melting temperature about 8 C above the melting point it dwells there for 90 minutes to permit the metal sample to melt The furnace then ramps down automatically to a temperature just above the melting point The controller holds at that temperature for approximately 20 minutes while every thing equilibrates after which the display flashes on and off alternately indicat ing tha
41. e 4 Rear Panel Manual Rev 970701 0000 Y 00000 O 5 Parts and Controls MANUAL ON 5 Parts and Controls Top Insulation Thermal Block Thermal Shunt Insulation Basket Cover Insulation Basket Sealed Cell Heaters Insulation Thermal Well Temperature Control Sensor Cell Pad Figure 5 Thermal Block Assembly 16 Manual Rev 970701 Hart Scientific 9260 5 5 2 5 5 3 5 5 4 5 5 5 5 5 6 5 6 5 Parts and Controls feedback to the controller Forced airflow around the assembly keeps the out side of the furnace cool Heaters The block assembly is heated by up to 1200 watts of heat There are 3 heated zones the main zone heaters heat the entire length of the block and the top and bottom zones heat their respective ends The end zone heating compen sates for losses out of the unheated ends These heaters are adjusted to pro vide the required temperature uniformity within the cell itself The adjustments are made by way of the keypad Basket The sealed cell is positioned within the basket which allows the cell to be eas ily inserted and removed and contains all materials should the cell be broken The top and bottom parts of the basket are made of aluminum bronze and pro vide thermal shunting across the top and bottom as well The lid and basket are removed separately with the tongs provided A cell pad in the bottom of the b
42. e thermometers to equilibrate for 20 minutes before making readings The plateau can last several days depending on how it is used When the plateau has ended the furnace may be turned to about 25 C and turned off or if desired the process may be repeated To repeat the process press SET and DOWN and use the UP or DOWN keys to find the F EEZE step Select by pressing SET The furnace temperature will drop to a temperature 8 C below the freezing point and dwell there as before The sample will freeze and the temperature will automatically rise to a temperature just below the melting point The furnace will hold there for a time until the cell and furnace have fully equilibrated At that time the display will flash indicating that the cell is ready to begin the melting process again It is initiated as before by selecting mM ELE step 8 4 Freezing Point Realization The freezing point is an established ITS 90 method This method first entirely melts the metal sample The furnace temperature is then carefully reduced to a temperature below the freezing point just low enough to induce freezing of the sample This temperature must be several degrees below the freezing point in order to overcome the sub cooling of the sample After recalescense initiation of the freeze as observed on a monitor thermometer the furnace temperature Is increased to a temperature just slightly below the freezing point This act
43. ed by continuous high temperature operation Follow all safety guidelines listed in the user s manual WARNING THIS EQUIPMENT SHOULD ONLY BE USED BY TRAINED PERSONNEL Table of Contents 6 Introduction 0 T T T a s sos s s x x Specifications and Environmental Conditions 2 1 SpecificationSs 00008 2 2 Environmental Conditions 2 3 Warranty eee ee ee Safety Guidelines Quick Start 0 a eee eae 4 1 Unpacking oe we ew DE He 42 Setup cuaran ORS Gee GS Kw DS E ES 43 Dry out Period 00 4 44 Power 0 0008 eee ee 4 5 Setting the Temperature 4 6 Changing Display Units Parts and Controls 0 000 5 1 Bottom Panel ctwaene aa dd 5 2 Front Panel pda HES 5 3 TopPane 0 5A Rear Panel sessao 5 5 Thermal Block Assembly 5 5 1 Thermal Block 4 285 aww ee ew ca a Da a 5 5 2 Heaters 2 a a 1 5 5 3 Basketl Sra SR BO 55 4 Thermal Shunt 22 4644 a oe ns 55 5 Insulation sc 2 2 sa s sk 5648 s a k as k weeks 5 5 6 Temperature Control Sensor a 5 6 Mini Fixed point Cells J 5 7 Comparison Blocks 5 7 1 BlockWellSizes
44. ent energy and permitting more calibrations during the freeze Allow the thermometers to equilibrate for 20 minutes before making readings Calibration must end before the end of the freezing plateau To continue use re melt the sample Press SET and DOWN Select the m amp Lt function and the controller will re melt the sample and the process may be repeated This function is convenient if the furnace is to be used again early the next day The sample can be melted overnight and be ready to freeze in the morning 9260 Manual Rev 970701 49 8 Fixed Point Realization CAUTIONS Use care in handling the metal fixed point cells They can be easily broken or contaminated Keep all items clean Clean with pure alcohol Handle with clean cotton gloves or clean paper Remove any inadvertent finger prints or other contaminants Do not drop the cell or basket into the furnace Do not drop a thermometer into the cell even a short distance Do not leave quariz thermometers in the preheat wells any longer than necessary to heat to temperature especially at the aluminum point Contamination may result Do not insert cells into a hot furnace Start from near ambient temperatures When all calibrations are complete manually set the tempera ture to about 25 C to prevent the furnace from heating unex pectedly the next time it is used The furnace can be turned off while hot and permitted to cool on its own 8 5 Test Probe Cal
45. er adjusting the end zones repeat Step 1 to check the temperature profile again If the temperature differences still exceed the recommended limits re peat Step 2 again Temperature Calibration For best results in realizing freezing or melting points the furnace should be accurate to at least 0 5 C and preferably to 0 3 C The accuracy should be checked periodically and adjusted if necessary For small adjustments at one temperature the simplified one point calibration procedure explained in Section 9 2 1 may be used For calibration over the entire range of the furnace the three point calibration procedure explained in Section 9 2 2 should be used For each procedure a quartz SPRT is needed in a addition to a thermometer readout that together provide an accuracy of 0 1 C or better One point Calibration This one point calibration procedure improves the temperature accuracy of the furnace at one point by adjusting the RO calibration parameter see Section 6 16 2 It may be used often to ensure the quality of a specific fixed point real ization The first step is to measure the furnace temperature at the temperature of in terest The furnace should have the fixed point cell installed and the cell must be entirely frozen or melted Measure the temperature with the SPRT fully in serted into the well Make sure the furnace temperature is stable and make careful and accurate measurements Manual Rev 970701 Hart Scientific 9 Furnace Ca
46. ess heater power in secondary menu E ting Proportional Band In a proportional controller such as this the heater output power is propor tional to the well temperature over a limited range of temperatures around the Manual Rev 970701 Hart Scientific 9260 6 Controller Operation set point This range of temperature is called proportional band At the bottom of the proportional band the heater output is 100 At the top of the propor tional band the heater output is 0 Thus as the 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 tempera ture The temperature stability of the well and response time depend on the width of the proportional band If the band is too wide the well temperature deviates ex cessively from the set point due to varying external conditions This deviation is because the power output changes very little with temperature and the con troller does not respond well to changing conditions or noise in the system If the proportional band is too narrow the temperature may swing back and forth because the controller overreacts to temperature variations For best control stability the proportional band must be set for the optimum width The proportional band width is set at the factory to about 5 0 C The propor tional band width may be altered by the user to optimize the control character Istic
47. grammed scan rates set points for each step in the process dwell times and an indication that the next step is ready Some of these pre programmed conditions can be modified by the user Temperature calibration should be checked occasionally to verify the set point temperatures Installing a Sealed Cell into the Basket The sealed cell is a very delicate instrument The quartz glass on the outside of the cell can be easily broken and easily scratched by the harder metal ma terials into which it is inserted CAUTION Sealed cells are designed to be kept upright They should be stored in this position as well Before inserting the cell be sure it is clean and free of finger oils Use pure or reagent grade al cohol to clean all pieces Quartz glass will devitrify breaking down the glass and eventually causing breakage or air leak age to the cell Clean the basket surfaces as well Use cotton gloves to handle the basket and cell after cleaning Each cell should have its own basket assembly Repeated in sertion and removal poses an unnecessary risk to the cell A cell pad of fiber ceramic fiber or quartz wool should be in the bottom of the basket to pad the cell This cell pad should not be too thick so as to prevent proper fitting of the basket cover Follow these steps to properly insert the sealed cell Refer to Figure 5 for loca tion of component detail Manual Rev 970701 43 8 Fixed Point Realization 44 10 11 1
48. he unit to prevent it from causing any damage The cooling air vents in the top of the unit permit heated air to exit the unit Care must be taken not to touch these vents while the furnace is at high temperatures or burns may result CAUTION Areas on the top of the furnace may be very hot due to hot air blowing upward Please use caution Rear Panel The rear panel consists of the inner melt heater connector the inner melt heater switch and the serial port See Figure 4 1 The inner melt heater plugs into the rear of the furnace into the connector provided Be sure it is plugged in during operation The inner melt heater switch can be set to MANUAL ON position or AUTO position The microprocessor has control when the switch is in the AUTO position The serial port is a DB 9 male connector for interfacing the instrument to a computer or terminal RS 232 communications Thermal Block Assembly The thermal block assembly is shown in Figure 5 and described below Thermal Block The thermal block is specifically designed to contain the sealed cell and bas ket containment assembly This design permits the uniformity to be tuned carefully for best performance and cell safety Heaters in the perimeter of the aluminum bronze cylinder provide heat as dictated by the temperature control ler APRT sensor in the block monitors the block temperature and provides Manual Rev 970701 Hart Scientific 9260 lt Figur
49. hermal block of the furnace in order to reduce stem conduction along the thermometer Heat loss from stem conduction will reduce the accuracy of the measurement Top Insulation A fiber ceramic pad of insulation is provided with the comparison block This insulation helps the thermal shunt by keeping it closer to the furnace tempera ture After it is inserted poke holes through it to match the comparison block Manual Rev 970701 Hart Scientific 5 Parts and Controls Ventilation Plate Insulation Model 3160 2 Thermal Shunt Comparison Block Model 3160 3 Thermal Block Assembly Temperature Model 3160 1 Control Sensor Figure 7 Comparison Blocks 9260 Manual Rev 970701 21 9260 6 Controller Operation 6 Controller Operation This section discusses in detail how to operate the furnace temperature con troller using the front control panel By using the front panel key switches and LED display the user may monitor the well temperature adjust the set point temperature in degrees C or F monitor the heater output power adjust the controller proportional band and program the operating parameters program parameters serial interface configuration and the controller calibration param eters Operation of the functions and parameters is shown in the flowchart in Figure 8 on page 24 This chart may be copied for reference In the following discussion a button with the word SET UP DOWN or EX
50. ibration For optimum accuracy and stability allow the furnace to warm up for 10 min utes after power up and then allow adequate stabilization time after reaching the set point temperature After completing operation of the furnace allow the well to cool by setting the temperature to 25 C and allowing the unit to cool off before switching the power off 8 5 1 Calibrating a Single Probe Insert the probe to be calibrated into the well of the instrument The probe should fit snugly into the comparison block yet should not be so tight that it cannot be easily removed Avoid any dirt or grit that may cause the probe to jam into the comparison block Best results are obtained with the probe in serted to the full depth of the well Once the probe is inserted into the well al low adequate stabilization time to allow the test probe temperature to settle as described above Once the probe has settled to the temperature of the well it may be compared to the furnace display temperature The display temperature should be stable to within 0 01 C degree for best results Never introduce any foreign material into the probe hole of the insert Fluids etc can leak into the furnace causing damage to the instrument or binding and damage to your probe 8 5 2 Furnace Characteristics There is a temperature gradient vertically in the test well Heat is applied to the block in such a way as to compensate for nominal heat losses out of the top of the furnace
51. interface If the sample rate is set to 5 the instrument transmits the current measurement over the serial interface approximately every five seconds The automatic sampling is disabled with a SPEr Flashes 5 P E Serial sample period parameter and then Se gees ect eee r rs 55 Sr S Current sample period seconds Press SET to store the sample period to the new value and to access the Duplex Mode Manual Rev 970701 33 6 Controller Operation 6 15 3 Duplex Mode The next parameter is the duplex mode The duplex mode may be set to full duplex or half duplex With full duplex any commands received by the instru ment via the serial interface are immediately echoed or transmitted back to the dUPL 3 Flashes d UPL Serial duplex mode parameter and then dis Cups S S enna ene plays he seting d FULL 3 Current duplex mode setting Press SET to store the duplex mode to the new value and to access the the Linefeed 6 15 4 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 Press SET to store the new linefeed value 6 16 Calibration Parameters The operator of the instrument has access to a number of the calibration con stants namely RO ALPHA DELTA top and bottom zone percent heat and the hard cut out These values are set at
52. ion over tem perature thermal cut out Heater 1200 W maximum adjustable top and bottom zones Heating Time Approximately 1 25 hours 25 C to 680 C Cooling Time Approximately 10 5 hours 680 C to 100 C Stabilization Time 15 minutes nominal Immersion Depth 229 mm 9 Power Requirements 115 VAC 410 60 Hz 11 amps maximum 10 amps nominal 230 VAC 10 50 Hz 6 amps maximum 5 amps nominal Exterior Dimensions 250 mm L x 203 mm W x 489 mm H 10 x 8 x 19 25 Weight 20 5 kg with comparison block 45 Ib Manual Rev 891101 3 2 Specifications and Environmental Conditions Table 2 Mini Cell Specifications Expanded Uncertainty Using 9260 Furnace Model Fixed Point Temperature Six 9 s Cell Five 9 s Cell 5914 Indium 156 5985 C 2mK 5 mK 5915 Tin 231 928 C 3 mK 5 mK 5916 Zinc 419 527 C 4 mK 7 mK 5917 Aluminum 660 323 C 10 mK 12 mK 2 2 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 temperature range 5 45 C 41 113 F e ambient relative humidity 15 50 e pressure 75kPa
53. ion restricts the amount of heat that can flow from the cell which controls the rate of freezing High temperature stability and good temperature uniformity permit the temperature to be adjusted closely achieving long freez ing plateaus Long freezing plateaus translate into a larger number of calibra tions that can be done during one freeze Measurements are made until the plateau begins to deviate and then the freezing must be completed and the process started over 8 4 1 Freezing Point Procedure The following procedure illustrates the steps required to successfully realize a fixed point temperature through freezing the cell sample Figure 11 illustrates the process graphically 8 4 1 1 Preparation The cell should be carefully loaded into the basket and then into the furnace according to the procedure previously outlined in Section 8 2 Thermometers that are to be inserted into the cell should first be cleaned with pure alcohol A 9260 Manual Rev 970701 47 8 Fixed Point Realization 250 240 230 220 Temperature C 210 200 190 Melting Complete q Cs CALIBRATION PERIOD Initiate FREEZE Freezing Plateau er MELT PERIOD __ lt MAINT PERIOD gt Melting of sample Maintains cell Manually Induce Compare Monitor PRT Initiate Values For Furnace MAINT MP 0 8 C Calibration Check yp 4 oC Start at Initiate MELT
54. justed 9 1 1 Step 1 Measure the profile The temperature profile should be measured at 660 C or at the highest fixed point with which the furnace is intended to be operated The furnace should have the fixed point cell installed and the cell should be completely frozen or melted Incorrect data will result if the cell is only partially melted or frozen Use a quartz SPRT and thermometer readout that together provide adequate resolution and stability to allow relative temperature measurements to 0 02 C or better You must wait until the temperature of the SPRT is stable before re cording readings It may take 20 to 30 minutes after inserting the SPRT before it becomes stable Measure the temperature at three locations t1 with the SPRT fully inserted into the well t2 with the SPRT withdrawn 6 cm 2 5 in and t3 with the SPRT withdrawn 12 cm 5 in To reduce possible effects of temperature drift repeat the measurements in the following order t1 t2 t3 t2 again then t1 again Wait until the SPRT is stable about two minutes before recording each reading Average the two t1 measurements and the two t2 measurements then compare the temperatures Temperature t2 relative to t1 should be less than 0 1 C higher or lower Temperature t3 relative to t1 should be between 0 and 0 2 C higher If the gradient exceeds these limits adjust the end zones as explained in the next step 9 1 2 Step 2 Adjust the end zones The temperature profile can be a
55. lashes nELE and then displays the value 100 00 Current melt temperature setting Adjust this parameter by using UP or DOWN Press SET to accept the new value and to display the freeze parameter SET Adjust this set point by using UP or DOWN Press SET to accept the new value and to display the maintain parameter SET Adjust this set point by using UP or DOWN 32 Manual Rev 891101 Hart Scientific 9260 6 Controller Operation Press SET to accept the new value 6 15 Serial Interface Parameters The serial RS 232 interface parameters menu is indicated by The serial interface parameters menu contains parameters which determine the operation of the serial interface These controls only apply to instruments fitted with the serial interface The parameters in the menu are BAUD rate sample period duplex mode and linefeed 6 15 1 BAUD Rate The BAUD rate is the first parameter in the menu The BAUD rate setting de termines the serial communications transmission rate The BAUD rate of the serial communications may be programmed to 300 600 1200 2400 4800 or Press SET to store the baud rate to the new value and to access the Sample Period 6 15 2 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 measurements transmitted from the serial
56. libration The next step is to adjust R0 to make the temperature closer to the set point Increasing or decreasing RO by 0 010 increases or decreases the temperature by about 0 025 C at 0 C and about 0 09 C at 650 C Use the following for mula to calculate a new value for R0 to make the temperature closer to the set point RO RO fmeas tsp pal bay Q 1002 For example with the set point at 655 C the furnace temperature is measured and found to actually be 655 65 RO is set to 100 124 ohms The new value for RO is calculated as follows RO 1001240 S S on 0520 C 605 C 2 5 Q 1009 9 2 2 Three point Calibration The first time the furnace is calibrated at the factory it is calibrated over the full range by adjusting the three calibration parameters RO ALPHA and DELTA This full calibration may be repeated periodically to ensure that the furnace is accurate to 0 5 C or better at all temperatures in its range Full calibration requires making measurements of the furnace temperature at three widely separated set points throughout the range of the furnace Sug gested set points are 50 C 400 C and 650 C The actual temperature of the furnace is measured at these temperatures As before the furnace should have the fixed point cell installed and the cell must be entirely frozen or melted Measure the temperature with the SPRT fully inserted into the well Make sure the furnace temperature is stable wait a
57. manufactured in the same careful manner as their larger full size counterparts The certified high purity metal sample must maintain its pu rity throughout the process of manufacture and use of the cell To accomplish this high purity materials must be used for all the other components of the cell After fabrication of each component it must be treated to remove any im purities that may have been added during the process The components are assembled in a clean environment and never touched directly by hand After the components have been assembled and the silica glass permanently sealed all of the air is evacuated out while the cell is melted Numerous cycles of vacuum and purging with high purity argon are finally completed when the evacuation port is sealed leaving approximately one atmosphere pressure of argon in the cell at the freezing point of the sample Temperature corrections must be made to the reading to account for actual cell pressure and for hydrostatic pressure During manufacturing the cell is sealed with argon near the 1 atmosphere pressure At that time the actual pressure is measured With that pressure a small temperature correction can be calculated The hydrostatic pressure created by the mass of the sample itself depresses the temperature of the reading Since different cell designs and thermometer designs translate to different immersion depths the practice is to calculate and correct for the error Figure 6 illustrate
58. mode parameter and then Spina may buka pia displays the setting Auto Current setting Press SET to accept the new parameter 6 14 Program Parameters The program parameters menu is indicated by Prob i Program parameters menu Press SET to enter the menu The Program parameters menu contains the fixed point parameter the curve parameter and the curve temperature param eter 6 14 1 Fixed point The first parameter in this menu is the Fixed point parameter The Fixed point parameter allows the user to select the fixed point metal The available options are In Induim Sn Tin Zn Zinc Al Aluminum or Other FP 3 Flashes F P Fixed point parameter and then displays the RR sss s nsn setting In Current Fixed point setting Indium 9260 Manual Rev 891101 31 6 Controller Operation Press SET to accept the new Fixed point parameter and to access the Curve parameter 6 14 2 Curve The next parameter in this menu is the Curve parameter The Curve parame ter is selected as either melting or freezing ere ee ting Press SET to accept the new Curve parameter and to access the Curve Temperature parameter 6 14 3 Curve Temperature The final set of three parameters in this menu are the Curve Temperature pa rameters These parameters set the temperature of the curve set points TEMP x Flashes TEMP Curve Temperature parameter and then dis nas sn B y amal p yamala MELE F
59. n ON Set scan function sc an on of f ON or OFF Turn scan function on sc an on sc on Turn scan function off sc an of f sc of Read scan rate sr ate sr srat 999 99 C or F min srat 10 0 C min Set scan rate to n degrees per minute sr ate n sr 5 1 to 99 9 Read program control pc pc pc STOP FREEZE ME LT pc FREEZE MA INTAIN Set program control pc stop freeze mellt malin pc melt STOP FREEZE tain MELT or MAINTAIN Secondary Menu Read heater power po wer po po 999 9 po 1 duty cycle Read proportional band setting pr op band pr pb 999 9 pb 15 9 Set proportional band to n pr op band n pr 8 83 0 1 to 100 Read set point resistance sr sr 999 999 121 091 Configuration Menu Operating Parameters Menu Read high limit hl hl hl 9999 hl 925 Set high limit hl n hl 900 100 1200 Read soft cut out cu cu cu 9999 9 cu 1150 Set soft cut out setting cu tout n Set soft cut out to n degrees cu tout n cu 500 0 0 to 1150 0 Read cut out mode cm ode cm cm xxxx cm AUTO Set cut out mode cm ode r eset a uto Reset or Auto Set cut out to be reset manually cm ode r eset cm r Set cut out to be reset cm ode a uto cm a automatically Program Parameters Menu Read fixed point parameter fp fp fo INDIUM TIN fo INDIUM ZINC ALUMINUM Set fixed point parameter fo INDIUM TIN ZINC fp In INDIUM TIN ALUMINUM ZINC ALUMINUM Read curve parameter crv crv crv MELT or FREEZE crv MELT Set curve parameter crv melt freeze crv melt MEL
60. ne heating bpct n bpct 150 0 O to 200 These commands are only used for factory testing Miscellaneous not on menus Read firmware version number ver sion ver ver 9999 9 99 ver 9260 v1 1 Read structure of all commands h elp h list of commands 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 the command is returned followed by a carriage return and linefeed Then the value is returned as indicated in the RETURNED column 9260 Manual Rev 970701 41 9260 8 Fixed Point Realization 8 Fixed Point Realization General Either a freezing or melting plateau may be realized The melting point is faster and easier than the freezing point method and the plateau can last lon ger Properly done accuracy of measurements is nearly the same Realizing the fixed point temperature is a matter of achieving the ITS 90 de fined temperature through a careful process The Hart Scientific Model 9260 furnace features an internally programmed method or a manual method to per form this process The internal programming procedure requires the user to 1 Select the point Indium Tin Zinc Aluminum or a user programmed point to be realized 2 Select either the freezing curve or melting curve mode 3 The controller then provides pre pro
61. nications may be programmed to 300 600 1200 2400 4800 or 9600 baud The BAUD rate is pre programmed to 2400 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 SPEr 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 instrument transmits the current measurement over the serial interface approximately every five seconds The 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 displayed value Duplex Mode The next parameter is the duplex mode indicated with su PL The duplex mode may be set to half duplex HALF or full duplex Fu L1 With full du plex any commands received by the instrument via the serial interface are im mediately echoed or transmitted back to the device of origin With half duplex the commands are executed but not echoed The default setting is full duplex The mode may be changed using UP or DOWN and pressing SET Manual Rev 970701 Hart Scientific 7 Digital Communication Interface 7 1 2
62. nt Realization 8 3 1 Melting Point Procedure The following procedure illustrates the steps required to successfully realize a fixed point temperature through melting the cell sample Figure 10 illustrates the process graphically 8 3 1 1 Preparation The cell should be carefully loaded into the basket and then into the furnace according to the procedure outlined in Section 8 2 Thermometers that are to be inserted into the cell should first be cleaned with pure alcohol The in ner melt heater should be inserted carefully into the cell 8 3 1 2 Setting Up The Controller Setup of the controller consists of selecting the fixed point and the curve to be used The setup is in the secondary menu of the controller menus Access the setup by pressing SET and EXIT Then press SET 4 times and UP until Prob is displayed Press SET FP fixed point flashes and then the cur rent setting is displayed This setting is the one used on the previous test Press UP or DOWN repeatedly to toggle through Indium Tin Zinc Alumi num and Other When you reach the desired fixed point press SET to select it Immediately after pressing SET CuRvE flashes and the current setting appears The available curves are melt and freeze Use the UP or DOWN key to select the MELT curve Press SET to select it Following the curve selection the term T En P flashes on the displ
63. ntrol probe at OC The value of this parameter is set at the factory for best instrument accuracy ALPHA This probe parameter refers to the average sensitivity of the probe between 0 and 100 C The value of this parameter is set at the factory for best instrument accuracy DELTA This probe parameter characterizes the curvature of the resistance temp erature relationship of the sensor The value of this parameter is set at the fac tory for best instrument accuracy should have a list of these constants and their settings with manual Top and Bottom Zone Percent Heating The top and bottom zone heaters of the furnace start heating each time the main zone heater turns on These end zone heaters are adjusted to a percent age of on time compared to the main zone Each zone is pre adjusted accord ing to a calibration procedure that provides a low vertical temperature gradient in the thermal block Manual Rev 970701 35 6 Controller Operation 6 16 5 1 Bottom Zone bot PCt is the percentage of the main heater value for the bottom zone Do not adjust this value unless you are following the procedure in Section 9 Cali bration Procedure of this manual Adjustment values range from 0 to 200 per cent 6 16 5 2 Top Zone toPPCt is the percentage of the main heater value for the top zone Do not adjust this value unless you are following the procedure in Section 9 Calibra tion Procedure of this manual Adjustment values range from
64. o the heater is determined by 9260 Manual Rev 891101 217 6 Controller Operation the duty cycle or the ratio of heater on time to the pulse cycle time By knowing the amount of heating the user can tell if the instrument is heating up to the set point cooling down or controlling at a constant temperature Monitoring the percent heater power lets the user know the stability of the well tempera ture 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 is displayed as a 100 00 Well temperature ser F co Access heater power in secondary menu SEL 3 Flashes ie P Heater power in percent To exit out of the secondary menu press EXIT and hold for a brief moment To continue on to the proportional band setting function press EXIT momen tarily or SET 6 10 Set point Resistance 6 11 The set point resistance is the resistance of the temperature sensor at the cur rent temperature Allow the temperature to stabilize at the desired set point before taking its resistance In order to calibrate the furnace temperature the set point resistance must be displayed Press SET and EXIT to enter the secondary menu and show the heater power Then press SET twice to access the set point resistance SET fexr Acc
65. on of the measuring period A melt heater inside the reentrant well is turned on for a short time creating a second zone of melted sample which is next to the thermometer during measure ments This action permits more accurate measurements and is similar to the technique used with a Triple point of Water cell Measurements are made until the plateau begins to deviate and then the melt ing must be completed and the process started over DD poa a a ori 3 t Calibration n n Restart Period Process o S N Lu i w eae say ene i a i ae Initiate nitiate o FREEZE _ _ MELI MP 0 8 C MELT Q D E ce df o Melting Plateau 5 T Remove Inner Melt Heater MP 8 5 BR Ge Heating Rate and insert pre heated asa o S OR PSS E e Monitor Thermometers O MELT Period gt FREEZE lt MAINT gt OO DR DR E Cremer sans a Te Iniates and Maintains Period PrEP 0 LL uuu uuu Heating and Equalization New Melt Furnace Temperature Inner Melt At Start pete Heater t bD Gos u yo Sus n ous asas Cell Sample Temperature Initiate Note Melt heater in cell at P P A Program MAINT beginning of procedure Melting and Freezing Advance Point Temperature x User Adjustable 190 E 3 0 100 200 000 600 700 Time minutes Figure 10 Melting Point Realization 9260 Manual Rev 970701 45 8 Fixed Poi
66. roller Operation ited by the natural heating or cooling rate of the instrument This is often less than 100 C minute especially when cooling The scan rate function appears in the main menu after the scan control func tion The scan rate units are in degrees per minute degrees C or F depending on the selected units Press SET to accept the new scan rate and continue ser Accept scan rate 6 6 Program Advance The program advance function allows the user to step through the maintain freeze and melt operations of the fixed point realization They are explained in detail in Section 8 on Fixed Point Realization SET bom Access program advance Adv Adv flashes Po MAINT Displays one of the functions MAINT FREEZE MELT or eae ee eee STOP Press UP or DOWN to view the desired function ser Accepts the new the operation 6 7 Temperature Scale Units To toggle between C and F press the SET and UP keys simultaneously when the temperature is displayed 6 8 Secondary Menu Functions which are used less often are accessed within the secondary menu Pressing SET and EXIT simultaneously and then releasing accesses the secondary menu The first function in the secondary menu is the heater power display See Figure 8 on page 24 6 9 Heater Power The temperature controller controls the temperature of the well by pulsing the heater on and off The total power being applied t
67. rols ITS 90 is based on these principles The ITS 90 temperatures defined at the freezing points of Indium Tin Zinc and Aluminum are among these and are achievable with the Hart Scientific 9260 Furnace In order to achieve the ITS 90 temperatures and maintain long flat plateaus the substance samples metals in this case must be very pure Typically 6 Reentrant Well Silica Glass Quartz Envelope High Purity Argon 1 Atmosphere at Freezing Point Approx 50 mm High Purity Graphite Crucible High Purity Metal Sample 215 mm Maximum Immersion Approx 133 mm qa 43mm Figure 6 Typical Sealed Mini Fixed Point Cell 18 Manual Rev 970701 Hart Scientific 9260 5 Parts and Controls nines purity is best Sometimes 5 nines purity is used for the lower price but at the cost of higher uncertainty and shorter plateaus The 9260 furnace utilizes a sealed mini cell construction The construction of the mini cell follows the pat tern of the full size cell The high purity sample is contained within a graphite crucible The graphite is free of contaminants and will not react with the metal maintaining the metal purity This material is all hermetically sealed within a silica glass quartz envelope The internal atmosphere is high purity argon In order to immerse the test thermometer into the high accuracy temperature zone of the cell a reentrant well is provided in the center of the cell These cells are
68. rtant components and their proper use 5 1 Bottom Panel The bottom panel consists of the removable power cord inlet the power entry module PEM and power switch and the fan See Figure 1 1 The removable power cord inlet is located underneath the furnace and plugs into an IEC grounded socket 2 The power switch is located on the power entry module PEM The PEM also houses the fuses Models are available for either 115 VAC 10 60 Hz or 230 VAC 10 50 Hz operation 3 The cooling fan inlet is at the bottom of the unit The cooling air circulating through the furnace keeps the electronics and the chassis cool Keep the area immediately around the furnace clear to allow adequate ventilation Foot Fan Power Entry Module Power Cord Power Switch Inlet Front Figure 1 Bottom Panel 9260 Manual Rev 891101 11 5 Parts and Controls 4 Three feet support the chassis permitting air space for the fan and access to the power entry module and power switch 5 2 Front Panel The front panel contains the digital display and the controller keypad See Fig ure 2 1 The digital display is an important part of the temperature controller be cause it not only displays set and actual temperatures but also displays var ious instrument functions settings and constants The display shows temperatures in units according to the selected scale C or F 2 The four button controller keypad allows easy setting of the
69. rted See Section 5 for more details Turn on the power to the instrument by toggling the switch on the power entry module located underneath the front of the furnace The fan should begin qui etly blowing air through the instrument and the controller display should illumi nate after 3 seconds After a brief self test the controller should begin normal operation If the unit fails to operate please check the power connection The display will begin to show the well temperature and the well heater will start operating to bring the temperature of the well to the set point tempera ture Manual Rev 970701 9 4 Quick Start 43 Dry out Period Before initial use after transport and anytime the instrument has not been en ergized for more than 10 days the furnace will need to be energized for a dry out period of 1 2 hours before it can be assumed to meet all of the safety requirements of IEC 1010 1 4 4 Power Plug the instrument power cord into a mains outlet of the proper voltage fre quency and current capability Typically this will be 11 amps maximum at 115 VAC 10 60 Hz 6 amps maximum at 230 VAC 10 50 Hz Turn the instrument on using the POWER switch underneath the unit The instrument will turn on and begin to heat to the previously programmed temperature set point The front panel LED display will indicate the actual instrument tem perature 45 Setting the Temperature section 6 3 explains in
70. s for a particular application The proportional band width is easily adjusted from the front panel The width may be set to discrete values in degrees C or F depending on the selected units The proportional band adjustment can 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 proportional band ser fexr Access heater power in secondary menu rs Flashes 5 Set point Resistance and then displays the set E aun na ting 160 095 Resistance in ohms ProP 3 Flashes Pr oP and then displays the setting 5 0 Proportional band setting To store the new setting press SET Press EXIT to continue without storing the new value ser Accept the new proportional band setting Manual Rev 891101 29 6 Controller Operation 6 12 Controller Configuration The controller has a number of configuration and operating options and cali bration parameters that are programmable via the front panel These are ac cessed from the secondary menu after the proportional band function by pressing SET Co n F 0 flashes and then the name of the first parameter menu PAR is displayed Pressing SET again enters the first of four groups of configuration parameters operating parameters program parameters serial interface parameters and calibration parameters The groups are selected us ing
71. s of the International Temperature Scale of 1990 ITS 90 This fur nace is intended for Calibration Laboratory use and not for field applications The 9260 permits simplified realization of either freezing or melting curves In ternal programming of the micro processor controller provides preprogrammed scan rates set points for each step in the process dwell timing and indication that the next step is ready ITS 90 points including Indium Tin Zinc and Alu minum are included In addition one other user defined point may be selected User defined non ITS 90 fixed points are useful for specific applications The 9260 furnace is available in 115 VAC 10 60 Hz or 230 VAC 10 50 Hz models The 9260 furnace may also be used as a dry well calibrator or as a tempera ture comparator Pre drilled inserts are available from Hart Scientific for this application Built in programmable features include e Temperature scan rate control e Fixed point programming e Eight set point memory e Adjustable readout in C or F The temperature is accurately controlled by Hart s hybrid analog digital con troller The controller uses a precision platinum RTD as a sensor and controls the well temperature with a solid state relay triac driven heater The LED front display panel continuously shows the current well temperature The temperature may be easily set with the control buttons to any desired tem perature within the specified range The furnac
72. s the maximum immersion depth within the mini cell The actual immersion depth is taken to the center of the sensor element of the thermometer This depth will vary and the thermometer manu facturer may need to be consulted Approximations can be made for typical types of thermometers since the hydrostatic error is small anyway and may be negligible for some requirements Refer to the cell manual for the equations and constants that need to be applied Due to the fragile nature of the fixed point cells extra care must be taken dur ing use and handling Do not handle it with bare hands use clean cotton gloves or equivalent Make sure anything that comes in contact with the cell is clean To remove contaminants wipe the cell down with a clean cloth and pure alcohol Quartz glass is subject to a process called devitrification The glass will break down at high temperatures during this process Oils in the skin and other contaminants can initiate or accelerate this process Contaminants introduced to the reentrant well of the cell from unclean ther mometers can cause the same problem In addition some types of metals can contaminate the platinum sensor in a quartz SPRT at high temperatures 650 C and up Clean all thermometers prior to testing Manual Rev 970701 19 5 Parts and Controls 5 7 5 7 1 5 7 2 5 7 2 1 5 7 2 2 5 7 2 3 Comparison Blocks The 9260 furnace can function either as a calibrator or as a comparator As a
73. t the cell is now ready to initiate the freeze Note The monitor thermometer temperature can be checked while the sample is melting provid ing a good check of its accuracy The control temperature can then be accu rately checked during this dwell period To initiate the freezing of the metal press SET and DOWN again Press the up and down keys until the term Fr EE ZE is on the display Press SET to select that mode and the controller selects a set point temperature a few de grees below the freezing point to begin the sample freezing process This lower temperature is to overcome the super cooling of the metal sample The cell temperature must be monitored with the monitor thermometer at this time in order to see when the cell starts to freeze The freeze is established when the cell temperature begins a sharp rise toward the freezing point recalesence Immediately insert a quartz glass rod that is at room tempera ture for approximately 2 minutes to create a thin layer of frozen metal This ac tion positions the change of phase right next to the thermometer which is necessary for high accuracy After removing the tube press SET and DOWN again and select A nt to maintain the furnace at a temperature just below the freezing temperature With the freeze plateau underway calibrations can now be made Use the pre heat wells to heat up the thermometers before inserting them into the cell preserving the lat
74. the factory and must not be altered The correct values are important to the accuracy and proper and safe operation of the furnace Access to these parameters is available to the user only so that in the event that the controller 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 manual DO NOT change the values of the instrument calibration con stants from the factory set values The correct setting of these parameters is important to the safety and proper operation of the instrument Manual Rev 970701 Hart Scientific co 6 16 1 6 16 2 6 16 3 6 16 4 6 16 5 9260 6 Controller Operation The calibration parameters menu is indicated by Press SET five times to enter the menu The calibration parameters R0 ALPHA and DELTA characterize the resis tance temperature relationship of the platinum control sensor These parame ters may be adjusted by an experienced user to improve the accuracy of the furnace Caution should be exercised when adjusting these parameters since they affect the accuracy of the set point value This pro cedure is explained in detail in Section 9 Hard Cut out This parameter is the temperature above which the unit shuts down automati cally The parameter is set at the factory to approximately 700 C and cannot be changed by the user R This probe parameter refers to the resistance of the co
75. v 970701 25 6 Controller Operation 6 4 6 5 1 6 5 2 If the set point value is correct hold EXIT to resume displaying the well tem perature Press UP or DOWN to adjust the set point value When the desired set point value is reached press SET to accept the new value and to access the temperature scale units If EXIT is pressed any changes made to the set point are ignored ser Accept new set point value Temperature Scale Units The temperature scale units of the controller can be set by the user to degrees Celsius C or Fahrenheit F The units are used in displaying the well tem perature set point and proportional band Press SET after adjusting the set point value to change display units Scan The scan rate can be set and enabled so that when the set point is changed the furnace heats or cools at a specified rate degrees per minute until it reaches the new set point With the scan disabled the furnace heais or cools at the maximum possible rate Scan Control The scan is controlled with the scan on off function that appears in the main menu alter the set point function Press SET to accept the present setting and continue ser Accept scan setting Scan Rate The next function in the main menu is the scan rate The scan rate can be set from 0 1 to 99 9 C minute The maximum scan rate however is actually lim Manual Rev 891101 Hart Scientific 6 Cont
76. y arise followed by suggested actions to take for fixing the problem 11 1 1 Incorrect Temperature Reading Power the unit on and watch the display If the first number displayed is less than 0005 the unit has been re initialized The unit needs to be repro grammed for R0 ALPHA and DELTA These numbers can be found on the Report of Calibration that was shipped with the unit 11 1 2 The unit will not heat or heats at half rate e Check the fuse If the fuse is blown the display should be out e Ifthe problem continues contact Hart Scientific Customer Support 11 1 3 The unit heats slowly e Check the Scan and Scan Rate settings The Scan may be on with the Scan Rate set low Note When in program mode the scan rate is automatically set 11 1 4 If the display flashes any of the following err 1 This error means there is a RAMerror err 2 This error means there is a NVRAM error err 3 This error means there is a RAMerror err 4 This error means there is an ADC set up error err 5 This error means there is an ADC ready error e Initialize the system by performing the master reset sequence If the unit repeats the error code contact Hart Scientific Customer Sup port for a re turn authorization and for instructions on returning the unit e Master Reset Sequence Hold the SET and EXIT keys down at the same time while powering up the unit The screen will display init 926

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