digital conductivity meter service manual
Contents
1. a 2 E g 9 8 Le R E A gt 4 6 al al 7 T y dos B E gf 4 Ra 8 e amp H K ipa A tes E gt le Y a HE E ig E le BAe E E 3 E g ES 3 A A 8 El z ang 8 q m a E g idg Eda 5 5 El y t Figure 12 The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 14 OF 142. 8 Remove the plug from the unmarked hole in the case between the ZERO and CAL holes to access R 20 CAL reference 7 9 Depress the calibrate switch C and adjust R 20 Cal reference voltage for a display or 400 1 7 10 Replace the plug removed in step 7 8 no additional adjustment of R 20 is necessary 7 11 The instrument is now electrically standardized and should read ZERO 000 001 CAL 400 001 500 CU BOX 500 001 and 100 CU BOX 100 001 7 12 The meter is then adjusted to the probe for proper fuel measurements Identify the probe constant by locating the number stamped on the probe Fig 3 Multiply that number by 10 and adjust R 18 CAL for that number Example Probe No 42 x 10 420 CAL adjust to 420 001 7 13 The meter is now properly calibrated for fuel measurements Refer to section 8 0 for operating procedure 8 0 TEST PROCEDURE 8 1 Attach probe to bottom connector on the conductivity meter 8 2 Depress measure switch M with probe OUT of fuel sample Reading should be 000 001 in approximately 3 seconds Figure 4 If reading is outside limits remove probe and recheck zero by depressing measure switch 8 2 2 If zero reading is outside of limits with probe removed perform calibration procedure outline in section 7 0 The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent
3. model 1152 Conductivity Meter has an internal battery checking circuit If batteries are weak the meter will read for a short time and shut itself off If batteries are very low the unit will not turn on 4 2 When battery replacement is indicated remove the 4 screws holding the back plate exposing the battery housing at the top of the meter 4 3 Remove the 2 screws on the battery housing and set housing cover to one side Figure 10 4 4 Observe the polarity markings and insert three new batteries as shown in Figure 10 Battery replacement must be 3 6 volt Alkaline Nema 1414A Emcee P N 152 90 5341 Any other battery replacement will invalidate the CSA and UL Intrinsically Safe Rating 4 5 Replace back panel check zero and calibration 5 0 CIRCUIT DESCRIPTION 5 1 Power Supply The model 1152 Digital Conductivity Meter uses 3 A 554 6 volt batteries as a single 18 volt power source Depressing either the measure or calibrate switches provides power to op amp 1 via D 1 or D 2 Op amp 1A compares the battery voltage to a positive output at 6 volt zener reference ZD 1 and provides a positive output at pin 1 if the battery voltage is above 13 volts This insures adequate voltage for good regulation via VR 1 VR 1 provides a 10 volt pin 1 and a 5 volt pin 2 output in reference to pin 4 The 5 volt pin 2 output in reference to pin 4 The 5 volt output is buffered with op amp 1B The 0 level reference voltage is developed using the o
4. of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE7 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL 8 3 Depress Calibrate switch C with probe OUT of fuel sample After 3 seconds reading should be 10 times the probe calibration number 005 Figure 5 Example Probe No 40 Meter Reading 400 5 or 395 to 405 8 4 Insert probe in fuel to upper holes and depress measure switch Report reading after 3 seconds for stabilization Due to the polarization of the fuel sample the apparent reading will continue to change Only the reading 3 seconds after depressing the measure switch is correct 9 0 PARTS LIST Batteries 3 required 152 90 5341 Display PC Board 152 03 0000 Pre Amp PC Board 152 04 0000 A D Converter PC Board 152 05 0000 Probe 152 09 0000 The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 8 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL MODEL 1152 DIGITAL CONDUCTIVITY METER PICOSIEMENS METER o Pro
5. DIGITAL CONDUCTIVITY METER SERVICE MANUAL MODEL 1152 SERVICE MANUAL PICOSIEMENS METER oe EMCEE ELECTRONICS INC 520 CYPRESS AVENUE VENICE FL 34285 941 485 1515 FAX 941 488 4648 The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 1 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL TABLE OF CONTENTS PAGE 1 0 GENERAL DESCRIPTION 3 2 0 TEST EQUIPMENT REQUIREMENTS 3 3 0 PRELIMINARY CALIBRATION CHECK 3 4 0 BATTERY REPLACEMENT 4 5 0 CIRCUIT DESCRIPTION 2 2 4 6 0 TROUBLE SHOOTING CHART 6 T0 CALIBRATION o Wo s as Ue at aa Ce et a 8 0 TEST PROCEDURE 4 2 7 90 PARTS TIST ie o e a ee e 8 10 0 ILLUSTRATIONS FIGURE 1 METER AND PROBE 49 FIGURE 2 PROBE ATTACHMENT lt 9 FIGURE 3 PROBE CALIBRATION NO Swe ay oO RO ee me ee OY FIGURE 4 OPERATING POSITION 10 FIGURE 5 CALIBRATION MODE 10 FIGURE 6 MEASURE MODE 10 FIGURE 7 ACCESSORY CABLE REEL 11 FIGURE 8 REEL METER ATTACHMENT 11 FIGURE 9 M
6. ETER INTERNAL VIEW 12 FIGURE 10 PC BOARD ASSEMBLY 13 FIGURE 11 CALIBRATION ACCESSORY 13 FIGURE 12 SCHEMATIC DIAGRAM 13 SERVICE AND WARRANTY POLICY See Service amp Warranty Manual The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 2 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL 1 0 GENERAL DESCRIPTION 1 1 The Emcee Digital Conductivity Meter model 1152 as shown in Figure 1 is a hand held battery operated instrument for determining the conductivity of fuel samples Technically the instrument is a high range ohmmeter capable of reading between 500 megohms 2000 CU and infinity 0 CU 1 2 The controls as shown in Figure 1 consist of a pushbutton switch marked M measure and a pushbutton switch marked C calibrate 1 3 Figure 2 shows the instrument with the probe attached and ready for fuel test 1 4 Figure 6 shows the instrument in operation with the probe in a fuel sample 1 5 The Accessory Cable Kit is shown in Figure 7 and 8 With this reel the instrument can be used to test fuel in a large storage tank 1 6 Figure 10 shows the instrum
7. N 152 03 0000 7 1 With the back panel removed set R 18 case hole marked CAL to approximately mid scale The exact setting is not important at this time however the voltage at A 15 should be approximately 1 0 volts above the zero reference A 14 7 2 Remove the probe if attached and depress the measure switch M Adjust R 19 case hole marked ZERO for a display of 000 1 The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 6 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL 7 3 Attach the CU substitution box directly to the conductivity meter using the 500 CU position 7 4 Depress the measure switch M and adjust R 18 CAL for a display reading of 500 1 7 5 Remove the substitution box and repeat the zero adjustment 7 2 if necessary If zero adjustment is necessary repeat 7 3 and 7 4 after readjusting zero 7 6 Attach the CU substitution box to the conductivity meter using the 100 CU position 7 7 Depress the measure switch M and read the display for linearity The display should read 100 1 If the display is outside of tolerance recheck zero and 500 CU positions 7
8. be Figure 2 Figure 3 The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 9 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL Figure 4 Figure 6 The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 10 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL Figure 7 Figure 8 The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 11 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL Figure 9 The informationcontained in
9. ent with the back removed and the plug in pre amp and analog to digital PC boards removed 1 7 Figure 11 shows the CU Substitution Box for complete calibration 2 0 TEST EQUIPMENT REQUIREMENTS 2 1 CU Substitution Box 2 2 Digital Voltmeter 10 megohm impedance 0 1 volt 001 0 20 volt 01 3 0 PRELIMINARY CALIBRATION CHECK 3 1 Attach probe to bottom connector on the conductivity meter 3 2 Depress measure switch marked M The display should indicate 000 001 after 3 seconds If the display does not indicate 000 001 remove the probe and recheck for zero If the meter will zero without the probe but not with the probe the probe should be rinsed with isopropyl alcohol and allowed to air dry before retesting If the meter will not zero without probe proceed to calibration procedure 3 3 Depress calibration switch marked C The display should indicate the number on the probe Figure 3 times 10 005 Example Probe No 42 Display 415 425 The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 3 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL 4 0 BATTERY REPLACEMENT 4 1 The
10. ide humidity effects Since this coating cannot be removed the components on this board should not be replaced Any failure of the pre amp board requires a new board assembly The operation of this board however is to develop a current from the 1 volt bias through the fuel sample to the op amp pin 2 Pin 2 is maintained at 0 volts via the positive feedback through R3 With no fuel between the probe electrodes the pre amp output should be zero This is adjusted with zero adjust potentiometer R 19 During the calibrate period the negative voltage from R 20 provides the bias source to the pre amp and a calibrate reference can be set 5 4 A D Converter PC Board P N 152 05 0000 The A D converter assembly is a plug in PC board The converter is basically a 0 1 999 volt 3 digit voltmeter The reference voltage for setting the A D gain is adjusted by setting R 18 for approximately 1 0 volts The final adjustment for this potentiometer however is dependent on R 3 tolerance and variations in the probe constant The pre amp output is fed to the A D converter which has an automatic zero adjustment therefore any output from the amp can be directly monitored The A D converter directly drives the liquid crystal display located on the display PC board The A D board can be factory repaired 5 5 Display PC Board P N 152 03 0000 The display board includes the power regulator reference voltage supply calibration adjustment controls liquid crystal disp
11. lay measure and calibrate switches and the interconnects for the A D and the pre amp boards The display board can be factory repaired The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 5 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL 6 0 TROUBLE SHOOTING CHART MALFUNCTION Meter does not zero Meter reads above or below calibration number during CAL check CU reading erroneous when CAL check is okay No Display Indication 7 0 CALIBRATION PROBABLE CAUSE Contaminated Probe Needs zero adjustment Needs CAL adjustment Contaminated or damaged probe Lack of supply voltage MEASURE CAL switch defective A D Converter defective 5 Supply In op CORRECTIVE ACTION Clean thoroughly with isopropyl alcohol and air dry Adjust zero as per 7 2 Check Pre amp output as per 7 0 Clean probe with isopropyl alcohol and air dry Inspect probe for physical damage Check electrical characteristics as per 7 0 Check connection and or replace batteries Replace Display PC Bd P N 152 03 0000 Replace A D PC Bd P N 152 05 0000 Replace Display PC Bd P
12. the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 12 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL Figure 10 CU CALIBRATION ACCESSORY g o UU LN ha 100 PS M Figure 11 The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 13 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL
13. utput on op amp 1B pin 7 From this reference point we now have a 5 volt source and a 5 volt source The 0 reference voltage is not attached to the case Resistors R 15 and R 16 make up a voltage divider to provide a 1 volt source which is tied to the case The 1 volt becomes the bias voltage for the fuel probe 5 2 CALIBRATE REFERENCE The calibrate voltage is supplied by Q 1 and is adjustable from 0 to 1 volt Q 1 is biased on in a saturation mode via R 14 when the calibrate switch is depressed The collector output is divided by R 21 and R 20 and the adjustable voltage is passed on to the pre amp When the measure switch is depressed R 13 reverse biases Q 1 and turns Q 1 off This action guarantees a 0 volt potential to the pre amp calibrate input The informationcontained in the accompanying document is proprietary and confidential and may not be copied in any manner whatsoever without prior written consent of Emcee Electronics Inc The document and the material therein may not be used for any purpose other than that intended by Emcee Electronics Inc COPYRIGHT 2002 EMCEE ELECTRONICS INC REVISION DATE FEBRUARY 23 1996 PAGE 4 OF 14 DIGITAL CONDUCTIVITY METER SERVICE MANUAL 5 3 Pre Amp PC Board P N 152 04 0000 The pre amp board is a separate plug in PC board Due to the extreme high impedance of the circuit this board is very sensitive to humidity After manufacture this board is coated with a conformal coating to reduce outs
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