This page last changed on Sep 24, 2009 by kgomes.

pH Meter Assembly Instructions


  1. Don't cut the leads on the Temp sensor AD22103 - Mount standing up with 0.25" leads to insure close proximity to housing.    Use a 0.25" Teflon sleeve on the center leg.
  2. Teflon sleeves on the outer row of the right angle 2x7 JTAG connector (prevent shorting to housing)
  3. Lift pins on U21 - 3 and 6.   Bend straight out.
  4. Stuff 1x10 header on pH meter / controller board, do not solder header to analog front end board (deliver as two pieces)
  5. Implement the following Engineering Change Notifications (ECN's)
    1. ECN #1
      1. Schematic Mistake on U8 LM337 to fix VAAiso- connection to Vin of LM337 (should be Vout)
        1. Cut trace under C34 going to the non-stripe end of C34
        2. Drill hole on pin 8 J17, tube the hole with teflon tubing
        3. Connect U8 - pin 1 to J17 - pin 8 and non-stripe end of C34

    2. ECN #2
      1. Silk screen on rev 1.0 shows opposite polarity for C66 - stuff backwards to silkscreen

    3. ECN #3
      1. Connect U14- pin22 to U14 - pin 30

    4. ECN #4
      1. Connect C60 Anode to C54 Anode

    5. ECN #5
      1. C32 and C33 have wrong polarity on silkscreen stuff opposite

 PCB Fabrication

  • MATERIAL TYPE: FR4 or 370HR
  • UNIT DIMENSIONS: 08.500 By 01.400
  • MATERIAL THICKNESS: 0.062"
  • ARRAY DIMENSIONS: 00.000
  • BOARD FINISH: SMOBC
  • ARRAY NUMBER UP:       0
  • COPPER WEIGHT: 1 oz  
  • ARRAY QTY:       0
  • INNER COPPER WEIGHT: 1.0  
  • TAB ROUTE: YES
  • SOLDER MASK SIDE: Both Sides
  • SCORING: NO
  • SOLDER MASK COLOR: Green
  • E.TEST OPTION: NO
  • LEGEND SILK SCRN: Top Side
  • 5% OVERAGE: yes
  • LEG SILK SCRN COLOR: White

pH Meter Board House Package

  1. Schematic and Parts Placement diagrams
  2. Bill of Material
  3. Parts Kit with PCB
  4. Deliver to Indtec

pH Meter Board Inspection

  1. Visual inspection: compare against 'example board' for missing or mis-placed parts
  2. Errors found on Indtec board #1
    1. Some tantalums are missing (6 of them)
    2. ECN for tantalum reversal not done (in backwards)
    3. ECN #1 not done correctly - trace not cut underneath C34 (V- measures -15v)
    4. Tantalum caps are missing (spares not retured from Indtec or lost or obscounded)
    5. R79 not stuffed (assembly error) - causes no clock to processor
    6. R69, R70 need 10 ohms, schematic incorrectly has 100K
    7. JTAG connector stuffed on wrong side of board - JTAG Emulator can't see device, USB FET sees low voltage
  3. Connect +12v, GND, RX and TX to controller board external interface (next to metal band)
  4. Connect a 4.5 Digit voltmeter to VPH and GND on controller board external interface
  5. Connect "Calibrations Inc" voltage standard to VPH and GND on J17
  6.  

Foce_Build_Jan_2009a.zip (application/x-zip-compressed)
Document generated by Confluence on Feb 03, 2026 16:22