Service Manual - John Morris Scientific
Contents
1. RANGESEL1 e TIMI TTT PE7 AN7 28 RANGESEL2 l l D 29 MOD CLK okokoloko 30 SER DEMORCLK1 2 a DEMODCLK2 rwrl 3 side PLAT 81180 y BCE AR 1 U15 EEN ora o U16 n CD4011B DGND HD61603 ND COMP CD4011B o o 1 ii H SS dl AIF ORONO THOM ON eie et mon MOM EEN m Ye moe ero tO O OHO puo oco vor roni LCD_PN_0701032 u u Su DORM MOM AO MON HD e Ge OD Om uxo co OO co xo r r r N R o 006000 GLOB EE gt Se D ICL Loo UU DOWN eere RANO c NO NN N eo 0 u u u fiy OD o oiov o eic O 099 LOIN GA om rans O LONE o ie A YD Important U15 Microcontroller is not field replaceable because it programed for a specific board during factory calibration E SS e SS vva CHAM to OND 0 Or N cor HOR 00 O e SEL o z ao oo oo u m w lt w lt a w lt m o o w w ow mc 22 10 Board Layout GROUND GROUND CLIP CLIP 23 11 PC Board Parts List Res 100K 1 1 4W 031204 041032 Pes Res ST 031249 KSE 031206 031207 031208 031247 031212 092806 031246 031213 Res 15 0K 5 1 4W 031216 pop cannon sn 031225 031229 069864 031202 060873 pug IC LMC6468 OPAmp O 031234 031236 Uo CIC CD4UBCN NAND 078935 031243 031146 031149 031148 031254 D BuacketlCD 031154 24 12 Disassembly Assembly Procedures NOTE The following procedure should only be performed by a qualified service technician Case Disassembly e While ap2. accuracy Conductivity Law Solution Instrument Cell Conductivity Conductance Constant S cm or mho cm S or mho x 1 cm mS cm or mmho cm mS or mmho x 1 cm uS cm or umho cm US or umho x 1 cm Solution Conductivity Cell Constant Meter Conductance Solution Conductivity Meter Conductance Cell Constant Platinization The electrodes of YSI 3200 and 3400 Series conductivity cells are coated with platinum black during manufacturing This coating is extremely important to cell operation especially in solutions of high conductivity The cell should be inspected periodically If the coating appears to be thin or if it is flaking off the electrodes should be cleaned and replatinized Properly maintained conductivity cells will perform for years without replatinizing Salinity Salinity is determined automatically from the Model 3100 conductivity and temperature readings according to algorithms found in Standard Methods for the Examination of Water and Wastewater ed 1995 The use of the Practical Salinity Scale results in values which are unitless since the measurements are carried out in reference to the conductivity of standard sea water at 15 C However the unitless salinity values are very close to those determined by the previously used method where the mass of dissolved salts in a given mass of water parts per thousand was reported Hence the designation ppt is reported by the instrument to pr
3. calibration process The readings after calibration are only as good as the calibration itself e Perform calibration at a temperature as close to 25 C as possible This will minimize any temperature compensation error Follow these steps to perform an accurate calibration of the YSI Model 3100 system with cell Selecta calibration solution which is most similar to the sample you will be measuring e For sea water choose a 50mS cm conductivity standard YSI 3165 or 3169 e For fresh water choose a ImS cm conductivity standard YSI 3161 or 3167 e For brackish water choose a 10mS cm conductivity standard YSI 3163 or 3168 2 Placeat least 3 inches of solution in a clean glass beaker 3 Insert the cell into the beaker deep enough to completely cover the electrodes Do not rest the cell on the bottom of the container suspend it above the bottom at least 1 4 inch 4 Gently tap the cell to remove any air bubbles and dip the cell in the solution 2 or 3 times to ensure proper wetting 5 Allow at least 60 seconds for the temperature reading to become stable 6 Press the MODE key until the instrument is in the mode that you want to calibrate in as follows e Temperature compensated conductivity C symbol flashing This mode will automatically compensate the calibration value to 25 C using a coefficient of 1 91 C e Conductivity C symbol NOT flashing This mode does NOT use temperature compensation 7 Press and rele
4. cell cleaning procedure Use the ENTER key to select a higher or lower manual range or to set system to Autoranging Refer to manual section which provides step by step procedures for the function you are attempting Turn instrument OFF and back ON Repair or replace board assy Turn instrument OFF and back ON Repair or replace board assy Use a YSI 3200 series cell if temperature readings or compensation are required Read solution of higher SYMPTOM POSSIBLE CAUSE ACTION temperature e Replace Cell Cable assy e Repair or replace board assy 18 SYMPTOM POSSIBLE CAUSE ACTION 11 Secondary Display reads ovr 12 Main Display reads LErr 13 Secondary Display reads rEr Temperature is gt 95 C In temperature compensated conductivity mode temperature exceeds the values computed using user defined temperature coefficient and or reference temperature In cell constant cal mode temperature exceeds the values computed using user defined temperature coefficient and or reference temperature The user has selected Temperature Compensated Conductivity or Salinity and the current cell does not contain a temperature sensor Temperature jumper is set to F and reading is 2199 9 F but 203 F 8 Circuit Description Power Supply Read solution of lower temperature Replace Cell Cable assy Repair or replace board assy Adjust user defined temperature coefficient se
5. in any solution known to etch platinum or gold 2 Remove the cell from the solution and rinse in several changes of distilled or deionized water Inspect the platinum black to see if replatinizing is required Storage Short term Store conductivity cells in deionized or distilled water Change the water frequently to prevent any growth that may cause electrode fouling Long term Rinse thoroughly with deionized or distilled water and store dry Any cell that has been stored dry should be soaked in distilled water until the electrodes appear black before use 13 5 2 Platinization The electrodes of YSI 3200 and 3400 Series conductivity cells are coated with platinum black during manufacturing This coating is extremely important to cell operation especially in solutions of high conductivity The cell should be inspected periodically If the coating appears to be thin or if it is flaking off the electrodes should be cleaned and replatinized Properly maintained conductivity cells will perform for years without replatinizing The 3100 can be used to replatinize the electrodes of the cell In addition you will need a 2 0Z bottle of platinizing solution YSI 3140 WARNING Before replatinizing the electrodes of a cell make sure that the cell is designed to have a platinum coating on the electrodes 1 Immerse the cell in the platinizing solution YSI 3140 Make sure that both electrodes are submerged 2 Press both the UP
6. on the number of ranges which must be searched in order to find the correct range for the sample During the range search the instrument will appear to freeze on a given reading for a few seconds then once the range is located will pinpoint the exact reading on the display The display may also switch to 00 0 for a second or two during a range search before it selects the proper range During normal operation the ENTER key enables and disables the autoranging feature of the instrument 4 Advanced Setup For highest accuracy the 3100 and cell may be calibrated as a system using standard conductivity calibration solution and the temperature coefficient can be adjusted 4 1 Cell Calibration Prior to calibration of the YSI Model 3100 it is important to remember the following e The cell constant must be set correctly before calibrating See Configure the 3100 Cell Constant e Always use clean properly stored NIST traceable calibration solutions When filling a calibration container prior to performing the calibration procedures make certain that the level of calibrant buffers is high enough in the container to cover the electrodes Gently agitate the cell to remove any bubbles in the conductivity cell e Rinse the cell with distilled water and wipe dry between changes of calibration solutions e During calibration allow the cell time to stabilize with regard to temperature approximately 60 seconds before proceeding with the
7. 3 4 Making Measurements After setting up the 3100 instrument and cell as described earlier the following basic steps should be used to make measurements 1 Verify that the 3100 is properly setup to use the current cell by measuring or calibrating with a standard conductivity solution 2 Immerse the cell in the solution to be measured 3 Gently tap the cell to remove any air bubbles and dip the cell in the solution 2 or 3 times to ensure proper wetting The cell electrodes must be submerged and the electrode chamber must not contain any trapped air If using a flow through or fill cell be certain it is completely full 4 Allow time for the temperature to stabilize 5 Press the MODE key to select the units required then read the display 6 Rinse the cell with distilled or deionized water 3 5 Autoranging amp Range Searching The YSI Model 3100 is an autoranging instrument This means that regardless of the conductivity or salinity of the solution within the specifications of the instrument all you need to do to get the most accurate reading is to put the cell in the sample When you first place the cell into a sample or calibration solution and again when you first remove the cell the instrument will go into a range search mode that may take as long as 5 seconds During some range searches the instrument display will flash rANG to indicate its movement from one range to another The length of the range search depends
8. ARROW and MODE keys at the same time The large portion of the display will show PLA flashing indicating that platinization is in process 3 After the platinization process is complete about 30 minutes the 3100 will return to normal mode Remove the cell from the platinizing solution If you want to stop the platinization before 30 minutes have passed press both the UP ARROW and MODE keys at the same time to abort 4 Thoroughly rinse the cell with distilled or deionized water 5 Promptly return the platinizing solution to its container 14 6 Test and Verification Procedure Connect the YSI Model 3100 as shown in Figure 1 next page and follow the charts below to verify it s electronic accuracy Test the system accuracy instrument and cell using conductivty standards See Cell Calibration Eguipment Reguired If using the YSI 3166 Precision Calibrator Set to simulate conductance a YSI 3232 adapter is reguired for proper connection to the cell connector Temperature can only be accessed using the YSI 003229 cable assembly See figure 1 If a decade resistance box is used to simulate conductance and temperature a YSI 003229 cable is required for connection to the cell connector Important Notes 1 Place the Model 3100 in conductivity mode with temperature compensation turned off C not flashing 2 Model 3100 cell constant set to 1 00 See Configure Cell Constant 3 The 3100 has no internal calib
9. Service Manual YSI Model 3100 Instrument Conductivity Salinity Temperature YSI INCORPORATED 1725 Brannum Lane Yellow Springs Ohio 45387 USA Phone 937 767 7241 800 765 4974 Fax 937 767 9353 e Inet info 9 ysi com Table of Contents 1 Introduction Pee EE 1 2 ulia condici OT Pc c dnd OS 3 3 System Configuration and Operation eere ee trece eese teens tn tn owo oO ed satu etn OOOO OO YDD en oO ene onn owo onn ow sues essa sn nS 6 3 1 Configure the 3100 eerte eg ESA 7 3 2 Cell Consta EE 7 3 3 Measurement Modes enu Een eee aee Ugo deb e d a eae EEN de e EAE E A 8 3 4 Makin amp MeasurementS iiu o o RO RR ERO RR i TROU BR rU PEN ERE 8 3 5 Autoranging amp Range Searching ENEE 9 4 Adyan ced E E 9 AN Coll Calibration EE 9 4 2 Setting the Temperature Coefficient jest e ee eevee e dece eee AEN 12 4 3 Reference Tree et ERE AE deed 12 AA Manual kan mgeleet E 12 5 Cel Maintenance X C M P 13 5 T Cleaning and Stota ges eee eet Er ee T me REB UE 13 S 2Platimnization sn E 14 6 Test arid Verification Procedure sccsssieseccsossesuseosssetseseosensasosntnessssniasebesnivtesnonseesovesecsusesebesuissbsesesessensesessancesbentagubesesetetoosenetees 15 REKT On E 17 8 Circuit Description EE 19 9 Schematic Diagrams geed 21 10 Board E E 23 11 PC Board Parts DE eminet D ER UE 24 12 Disassembly Assembly Procedures aisscseccescocescosssssasesssususosva
10. UL CSA CE 95 RH non cond 9x95 x4 4 inches 2 6 pounds Frequency 70 Hz 70 Hz 240 Hz 1562 Hz 1562 Hz 22 9 x 24 1 x 11 2 cm 1 1 kg
11. ase both the UP ARROW and DOWN ARROW keys at the same time The CAL symbol will appear at the bottom left of the display to indicate that the instrument is now in Calibration mode 8 Use the UP ARROW or DOWN ARROW key to adjust the reading on the display until it matches the value of the calibration solution you are using If you are calibrating in temperature compensated conductivity mode enter the value at 25 C If you are calibrating in conductivity mode not temperature compensated enter the value the calibration solution should read at the current temperature 10 9 Once the display reads the exact value of the calibration solution being used press the ENTER key The word SAVE will flash across the display for a second indicating that the calibration has been accepted The YSI Model 3100 is designed to retain its last calibration permanently Therefore there is no need to calibrate the instrument after power down 11 42 Setting the Temperature Coefficient Follow these steps to modify the temperature coefficient of the Model 3100 1 Press and release the DOWN ARROW and MODE keys at the same time The CAL symbol will appear at the bottom left of the display and the large portion of the display will show 1 91 or a value set previously using Advanced Setup 2 Use the UP ARROW or DOWN ARROW key to change the value to the desired new temperature coefficient 3 Press the ENTER key The word SAVE
12. ctivity cell platinization is provided by U6a and U6b which open the main feedback loop and use the system reference voltage as the programming voltage for the current source The current source is clocked at 0 05HZ to provide platinizing current which switches polarity every 10 seconds Temperature is measured by a thermistor connected to the input of buffer amp U7 Current through the thermistor is supplied from the system reference through precision resistor R23 The output of U7c is connected to the temperature channel of A D MUX U6c Analog to digital conversion is done by dual slope integrator U13 U13 TSC500A is the analog half of an A D which provides all of the signal switching and buffering functions but leaves the timing and control to the system controller 20 9 Schematic Diagrams E Zeg gH Hc4086 U6 VDD poru Sio Ag Gy7 ond side GND air ft IL SEET ES SE ERR P Eege Ce C 7 DEMOD 15uH a 2 b AO AO M W010 ASND a af wp e n V PLAT C TSEL Z Z RIVE2 DEMOD 21 Ve POWER xi 20pF 4MHz C30 DGN 1 1 1 26 DN DN RNI 100 100k 100k 6 8 2 COMPLY e i ien CREF 4 KE WONDDEL LL 4 1524 RO Sour Te pl a SE MC68HC711E9CFNP 32 DGND 5 TSC500 n L N nwn oo an g 8 LSU DZ 2 N 15 PE1 ANT n Ve euo L DGND PE2 AN2 7 DU Ew ND PES AN3 E He PE4 AN4 C TSEL 1 R3 SE PES ANS DN 35748 PERANG
13. e Temperature Coefficient or reference temperature see Reference Temperature Use a YSI 3200 series cell or turn off temperature compensation Set jumper to read C Repair or replace board assy Power is input at JP2 12V nominal US regulates this input voltage to approximately 5v and supplies it to U9 which is always powered even when the instrument is off R26 pulls the power switch line up to 5v U9 pin 13 is pulled back low when the power button is depressed The micro U15 holds the power on through UO U9 pin 8 gt 4v and U9 pin 11 1v Regulator U10 has a 6 volt output which is set by divider R28 amp R29 U10 shuts down when pin 5 is low C18 amp 19 are output caps U11 is a 5 to 6v charge pump it should output negative 5 to negative 6 volts on pin 5 C22 is its output capacitor Digital Section U15 system microprocessor runs when pin 17 is high and the crystal is oscillating U14 will pull the reset line low under low input power conditions R33 R34 and R43 are not required so may not be installed on all boards Serial port JP4 is used for factory calibration only Data is output to the display driver chip in four bit nibbles on port B U16 drives the LCD The LCD holder and conductive strips zebra strips must be mounted flush to the PCB board and the connections kept clean for the LCD to properly operate 19 Analog Section The Model 3100 uses the Forced Current measurement technique This t
14. e and rotate the lower case into place on the upper case Make sure all four snaps are fully engaged Press firmly down on the three rear snaps to make sure they are completely engaged 25 13 Replacement Parts and Accessories mo ELISEUS YE mee Iessen mm vet window mm foward mm Wmm 700 per LLYS O pues ecm Emus wees mme Ines mm Jeepen mme LINCS Emus memes mm eeneg mme eem 26 14 Instrument Specifications Modes Conductivity Salinity Temperature Temperature Compensation Cell constant cm Power Adaptor Instrument Power Approvals Conductivity Temperature compensated conductivity Salinity Temperature Range 0 49 99 uS 0 4999 uS 0 4999 uS 0 49 99 mS 0 499 9 mS Range 0 80 ppt NaCl Range 5 95 C Environmental requirements Size Weight Requires a cell constant of K 0 01 K 0 1 or K 1 Requires a cell constant of K 0 1 K 1 or K 10 Requires a cell constant of K 1 or K 10 Requires a cell constant of K 10 Method Ref temp 9C Temp Coefficient Accuracy Resolution X 0 590 full scale 0 01 uS tX 0 590 full scale 0 1 uS X 0 590 full scale 1 us X 0 590 full scale 0 01 mS X 0 590 full scale 0 1 mS Accuracy Resolution 2 or 0 1 ppt 0 1 ppt Accuracy Resolution t 0 1 C Linear 15 25 0 4 C 0 01 0 08 0 12 0 8 1 2 8 12 AC 115V 220V 12 VDC 300mA max
15. e of 100 micro ay E mhos 100 microsiemens and a cell I fe se constant of 0 1 cm al K kxK R s 100 U mho x 0 1 cm ky 10 u mho cm bu In SI units the cell constant K 0 1 cm would become K 10 m and the same conductivity would be expressed N kxK 100 uS x 10 m IuS m Cell Constant The cell constant K is used to determine the resistivity or conductivity of a solution It is defined as the ratio of the distance between electrodes d to the area normal to the current flow A Cells with constants of 1 0 cm or greater normally have small widely spaced electrodes while cells with constants or 0 1 cm or less have larger electrodes that are closely spaced Cell Constant Calculation Anytime the condition of the conductivity cell changes it 1s possible that the cell constant has also changed Therefore you should calibrate your system regularly If you want to manually calculate your cell constant measure the conductance of a standard solution and compare with the theoretical conductivity of the solution The formula for determining the cell constant is N K k where K cell constant in cgs metric units cm 1 k measured conductance in p mho X theoretical conductivity in u mho cm The measured conductance k and conductivity X must either be determined at the same temperature or corrected to the same temperature for the equation to be valid One main reason for cell constant calibration is to increase overall system
16. echnique uses a voltage mode feedback loop around a square wave current source so that the output of the current source generates a fixed AC voltage across the conductivity cell Since the current required to produce a fixed voltage across the cell is proportional to the conductance of the cell the DC programming voltage to the square wave current source is proportional to the conductance of the cell Ul is a switched capacitor device that converts the DC programming voltage to a symmetrical square wave which provides the floating reference voltage for current source U2a Ul gets its clock from the system controller via level shifter Q1 Current source U2a uses reference resistors R5 R8 as selected by analog switch U3 which provides four decade ranges of cell current The cell drive current is supplied by U2a and returned through inverting current sink U2b which provides a cell drive that is symmetrical with respect to circuit common The potential across the cell is buffered by U2c and U2d and sampled by U4 acting as a synchronous demodulator to convert the cell potential into a DC voltage The demodulator uses a center sampling technique to minimize both series and parallel capacitance errors The demodulator output is compared to a reference voltage of 120mV by integrating comparitor U5 which provides the reference voltage for the square wave current source and the input voltage for the conductivity channel of the A D converter MUX U6c Condu
17. entals Electrical conductance k is defined as the ratio of the current I in a conductor to the difference in the electrical potential V between its ends k I V measured in mhos or siemens S Conductance therefore is not a specific measurement Its value is dependent upon the length of the conductor Conductivity X or specific conductance is the conductance per unit of conductor length For our purposes conductivity is defined as the conductance in mhos or siemens measured across the sides of a one centimeter cube of liquid at a specified temperature Looking at our electrodes as sides of a cube it becomes apparent that the conductance changes as the geometry of the cube changes If the cube lengthens with respect to the area of the e sides then the conductance will decrease If the area of the sides increases with respect to the distance between them then the ley qe conductance will increase The conductivity however will remain the same regardless of the geometry provided that the temperature and composition of the measured solution remain constant A factor called the cell constant K relates conductivity to conductance The cell constant is defined as the ratio of the distance between the electrodes d to the area normal to the current flow A d Cell Constant K A x kxK Therefore conductivity equals conductance multiplied by the cell constant K 1 0 cm K 0 1 cm Example For an observed conductanc
18. ervice Calibration is reguired Cell is contaminated Temperature coefficient has been set incorrectly Reference temperature incorrect Readings are or are not temperature compensated Conductivity Reading is over range gt 112 uS with K 0 01 cell gt 11 2 mS with K 0 1 cell gt 112 mS with K 1 cell gt 499 9 mS with K 10 cell Salinity reading is gt 80ppt User cell constant cal is over the limit of the current range User cell constant cal is under the limit of the current range User has selected manual ranging amp sample exceeds selected range Conductivity reading is over the range of the instrument gt 499 9 ms Incorrect sequence of key strokes System has failed its RAM test check procedure System has failed its ROM test check procedure Current cell does not contain a temperature sensor such as YSI 3400 series Temperature is 5 C 17 Check power supply and AC outlet Repair or replace board assy See Cell Calibration Repair or replace board assy Board needs factory calibration See Cell Calibration See Maintenance See Temperature Coefficient See Reference Temperature See Measurement Modes In all cases check calibration values and procedure check Advanced Setup settings Set cell constant to correct range If each of these is set correctly repair or replace board assy Set cell constant to correct range Recalibrate using known good conductivity standard Follow
19. es e Adjustable reference temperature 15 to 25 C Automatic temperature compensation Adjustable temperature compensation factor 0 to 490 C Adjustable Cell constant ranges 0 01 0 08 0 12 0 8 1 2 8 12 Auto or manual ranging Conductivity or Salinity readings 7 pin mini DIN connector with thermistor connections AC line power Service Philosophy The YSI Model 3100 is designed so that service can be performed easily by replacement of components or entire sub assemblies A snap together case reduces disassembly time and eliminates the need for elaborate tools Most service issues that occur in conductivity systems are caused by improper maintenance of the cell For this reason troubleshooting efforts should be initially directed at determining the condition and functionality of the cell and or cable In the event that a problem is isolated to the instrument itself YSI recommends replacement of the entire defective sub assembly rather than the individual components To lessen down time YSI maintains an adequate stock of replacement sub assemblies After servicing the Verification Test should be performed to insure that the Model 3100 is working properly If components on the printed circuit board have been replaced as part of the repair and this test fails the 3100 will need to be returned to YSI for factory software calibration or the printed circuit board will have to be replaced 2 Principles of Operation Conductivity Fundam
20. lue which would have been read if the sample had been at 25 C or some other reference temperature which you choose See Advanced Setup NOTE Requires YSI 3200 series cell Salinity A calculation done by the instrument electronics based upon the conductivity and temperature readings NOTE Requires YSI 3200 series cell Temperature Always displayed To choose one of the measurement modes temperature is always displayed simply press and release the MODE key Carefully observe the small legends at the far right side of the LCD Temperature Compensated Conductuctivity Salinity Conductivity with C with C with C If the instrument is reading Temperature compensated conductivity the large numbers on the display will be followed by either a US or mS and the small portion of the display will show the C flashing on and off If the instrument is reading Conductivity the large numbers on the display will be followed by either a pS or mS but the small portion of the display will show the C NOT flashing If the instrument is reading Salinity the large numbers on the display will be followed by a ppt NOTE Temperature compensated conductivity and salinity modes cannot be used unless a YSI 3200 series cell is connected When using a YSI 3400 series cell or equivalent with the 3232 cell adapter these modes will display an error message LErr since 3400 series cells do not contain a temperature sensor
21. of the ENTER key will cycle the Model 3100 through the four available manual ranges and return the instrument to autoranging NOTE You may see an error message in some manual ranges if the range selected is not adequate for the sample you are measuring If this happens simply press and release the ENTER key again until a range is selected which is suitable for your sample If you get lost and don t know if you re in a manual range 12 or autoranging simply turn the instrument off and back on The instrument will default to autoranging when first turned on The YSI Model 3100 has five possible ranges The number of ranges available for use depends on the current cell constant NOTE Cells may be used beyond their normal range but with instability and or reduced accuracy 5 Cell Maintenance 5 1 Cleaning and Storage The single most important requirement for accurate and reproducible results in conductivity measurement is a clean cell A dirty cell will change the conductivity of a solution by contaminating it Cleaning the Cell 1 Dip or fill the cell with cleaning solution and agitate for two to three minutes Any one of the foaming acid tile cleaners such as Dow Chemical Bathroom Cleaner will clean the cell adequately When a stronger cleaning preparation is required use a solution of 1 1 isopropyl alcohol and 10N HCl or Sulfuric Acid or Ethanol or Methanol CAUTION Cells should not be cleaned in aqua regia or
22. ovide a more conventional output Temperature The Model 3100 system utilizes a thermistor of sintered metallic oxide which changes predictably in resistance with temperature variation The algorithm for conversion of resistance to temperature is built in to the Model 3100 software and accurate temperature readings in degrees Celsius or Fahrenheit are provided automatically No calibration or maintenance of the temperature sensor is reguired 3 System Configuration and Operation Plug the power supply 300 ma minimum 12 VDC into its mating connector on the back of the instrument Depress e on off key to turn the instrument on The instrument will activate all segments of the display for a few seconds which will be followed by a self test procedure which will last for several more seconds During this power on self test sequence the instrument s microprocessor is verifying that the instrument is working properly The Model 3100 will display the current cell constant when the self test is complete 1 0 Cell constant e CEL Lo If the instrument were to detect a problem the display would show a continuous error message For a list of these error messages see the Troubleshooting chapter After the instrument completes this diagnostic routine the following screen should be displayed with no cell connected 0 00 5 udr 3 1 Configure the 3100 Before operating the 3100 or whenever you change cells you must config
23. plying slight separation force to the front curved edge of the case near one corner use a small straight blade screwdriver to release the snap A on the same side e When that snap releases keep applying the separation force and use the screwdriver to release the front snap B nearest the same corner e Repeat the procedure on the other corner to release both front and both side snaps e Swing the case open slowly pivoting on the three rear snaps C until they release e Lay the lower case assembly to the side 12 2 PC Board Removal e Gently release the two snaps nearest the front curved edge of the unit e With the snaps released lift the front of the board slightly and slide the board out of the rear connector openings PC Board Re installation e Remove the protective covering from the display DO NOT TOUCH THE FACE OF THE DISPLAY FINGERPRINTS AND DUST CANNOT BE EASILY REMOVED e Slip the connector end of the board into place against the gaskets at the rear of the case then rotate the board down into position engaging each snap as you go Be sure that the switch extenders line up with the switches e Inspect the assembly to insure that all board snaps are fully engaged and the board is in the proper position in the case Turn the assembly over and activate each switch Be sure you can hear and feel each switch click as it is pressed Case Re assembly e Hook the three snaps at the rear of the case into plac
24. ration Opening the case should only be attempted by a qualified service technician or permanent damage may result Conductance Verification Resistance Input Cell 3100 Range Displayed Connector Conductance 10 00 O x 0 296 499 9 mS 100 0 2 6 mS 100 00 Q 0 1 49 99 mS 10 00 26 mS 10 0 KQ 0 1 499 9 uS 100 0 2 6 uS 100 0 KQ 50 190 49 99 uS 10 00 26 uS 1 000 MO 0 196 49 99 us 1 00 25 uS Temperature Verification Temperature Resistance Input Cell Displayed Temperature Connector Pin 1 amp 2 1000 0 Q z 0 190 4999 us 1000 26 uS 5329 O 2596 40 0 2 C 15 1752 O 2596 70 0 2 C 3100 Rear Panel Decade Cell Thermistor Resistance 10K O6 25 C Box Red Brown Drive Blue Sense YSI3166 or Decade Resistance Box Yellow Drive White Sense Cable Mini DIN Conductivity Conn Cell VST 4 103220 3100 s 7 Pin Mini DIN Cell Connector Figure 1 16 7 Troubleshooting SYMPTOM POSSIBLE CAUSE ACTION Instrument will not turn on Instrument fails verification test System readings are inaccurate Instrument and cell combination Main Display reads OVEr Main Display reads Undr Main Display reads rErr Main Display reads PErr Secondary Display reads Err ra Secondary Display reads Err ro Secondary Display reads udr Power supply failure Instrument failure Incorrect calibration procedure Board reguires s
25. ure the 3100 to match the cell used You must enter the manufacturer s stated or your manually calculated cell constant K as shown below Cell Constant The default configuration is as follows e Cell constant of K 1 e Temperature compensation corrected to 25 C using a coefficient of 1 91 C 3 2 Cell Constant Follow these steps to change the cell constant 1 With the instrument on press and release the DOWN ARROW and MODE keys at the same time The CAL symbol will appear at the bottom left of the display and the large portion of the display will show 1 91 or a value set previously using Setup 2 Press and release the MODE key The large portion of the display will show 25 0C or a value set previously using Setup 3 Press and release the MODE key again The large portion of the display will show 1 00 or a value set previously using Setup 4 Use the UP ARROW or DOWN ARROW key to change the value to the desired new cell constant 5 Press the ENTER key The word SAVE will flash across the display for a second to indicate that your change has been accepted The 3100 will return to normal operation mode 3 3 Measurement Modes The Model 3100 is designed to provide four distinct measurements Conductivity A measurement of the conductive material in the liquid sample without regard to temperature Temperature Compensated Conductivity Automatically adjusts the reading to a calculated va
26. venseseovensesvasesssosswsutoosssentesuovedcosisobadesnsusucbonsnenteseavectvavescesbsvseteto 25 12 2 PG Board Removal eet e e ette E co ee ET aah ERE EA UE IEEE OLG 25 13 Replacement Parts and Accessories eene eee esee eee stent sso ense o e sae oo sae on tenens ve svedrov oin AO OOOO spese oso sae on sensn ono 26 14 Vru e HU AEIMU ICE CT M M M 27 A31043A i 031043 1 Introduction The YSI Model 3100 is a microprocessor based instrument designed to perform laboratory measurement of conductivity salinity and temperature The instrument s push button operation makes it simple to use The Model 3100 s microprocessor allows the system to be easily calibrated with the press of a few keys Additionally the microprocessor performs a self diagnostic routine each time the instrument is turned on The self diagnostic routine provides you with useful information about the cell constant function of the instrument circuitry and the quality of the readings you obtain The system simultaneously displays temperature in C along with one of the following parameters conductivity temperature compensated conductivity in US cm or mS cm and salinity in parts per thousand ppt You can switch back and forth from salinity conductivity and temperature compensated conductivity with a single push of the MODE key Capabiliti
27. will flash across the display for a second to indicate that your change has been accepted 4 Press the MODE key two times to return to normal operation the CAL symbol will disappear from the display 4 3 Reference Temperature Follow these steps to modify the reference temperature of the Model 3100 1 Press and release the DOWN ARROW and MODE keys at the same time The CAL symbol will appear at the bottom left of the display and the large portion of the display will show 1 91 or a value set previously using Advanced Setup 2 Press and release the MODE key The large portion of the display will show 25 0C or a value set previously using Advanced Setup 3 Use the UP ARROW or DOWN ARROW key to change the value to the desired new reference temperature the allowable range is 15 C to 25 C 4 Press the ENTER key The word SAVE will flash on the display for a second to indicate that your change has been accepted 5 Press the MODE key to return to normal operation 44 Manual Ranging If your application is easier to perform using a manual range that you select the YSI Model 3100 allows you to turn off the default autoranging feature While you are making conductivity or temperature compensated conductivity measurements simply press and release the ENTER key Each additional press of the ENTER key will cycle the Model 3100 to a different manual range until you return again to autoranging Five pushes
Download Pdf Manuals
Related Search