Sartorius PT-10 User manual

WPT5005-e02081
Service Manuals
Sartorius Troubleshooting
PT-10, PT-10P
Portable pH/mV-Meter

2
Contents
03 Service Policy for Exchanging Portable pH/mV
Meters (PT-10)
03 Troubleshooting PT-10
03 Testing the UP-10 Meter
04 Testing the pH Electrode
05 Quick Calibration
05 Complete Calibration
06 Changing Keypad
09 Changing Display
12 Changing Main PCB
17 Changing Battery Connector

3
Service Policy for Exchanging Portable pH/mV Meters (PT-10)
- Defective meters shall be exchanged for new ones and will be sent to our
central repair workshop (ZW) in Goettingen, Germany, for reworking.
- At your special request, meters can be sent to ZW in Goettingen for repair.
- Our warranty terms and conditions shall apply to all requests for repair.
Troubleshooting PT-10
Testing the UP-10 Meter
•Place meter in mV mode
•Press setup and then enter
This will clear out any offset that might be plugged into the meter
•Place the shorting cap on the BNC
•The reading should be stable at 0 ± 0.1 mV plus long term drift (0.1 mV per
month)
•Outside of this range may indicate a bad meter. Go to calibration section of
service manual.
•If meter passes this test, the meter is good. Go to electrode test below.

4
Testing the pH ElectrodeTesting the pH Electrode
Testing the pH ElectrodeTesting the pH Electrode
Testing the pH Electrode
•Connect the pH electrode to the BNC connector
•Place the clean electrode into a pH 7 buffer
•Place in mV mode: reading should be 0 ± 30 mV
Outside of this range indicates a bad electrode
•Place the clean electrode into a pH 4 buffer
•Press mV: reading should be 159 to 186 mV more than value in pH 7
Example: pH 7 buffer reads 10 mV; therefore,
the 4 buffer should read between 169 to 196 mV
•Place the clean electrode into a 10 buffer
•Press mV: reading should be 159 to 186 mV less than pH 7
Example: pH 7 buffer reads 10 mV; therefore,
the 10 buffer should read between -149 to -176 mV
•If electrode passes this test, confirm that the correct buffer set is selected. Then
clear buffers and re-standardize.
•If electrode fails this test, refer to electrode instructions on reconditioning
electrode.

5
Quick Calibration
1. Place the shorting cap on the BNC connector.
2. Press the mode and enter keys simultaneously.
3. The instrument will display „CAL“ on the screen. When the countdown is
finished the meter is calibrated.
4. If the reading is now 0 +/- 0.1 mV (7.00 pH) calibration was successful. If the
reading is outside of this range or unstable, replace the main PCB board.
Complete Calibration
NOTE:NOTE:
NOTE:NOTE:
NOTE: Only perform this calibration sequence if you have a calibrated precision voltage
source with an accuracy better than 0.1 mV and a 10 kohm resistor.
1. Press the mode and enter keys simultaneously.
2. Input 0.0 mV and wait for the countdown to be completed.
3. Input 1999.0 mV and wait for the countdown to be completed.
4. Input –1999.0 mV and wait for the countdown to be completed.
5. Input 0.0 mV and wait for the countdown to be completed.
6. Place the 10 kohm resistor in the ATC plug and wait for the countdown to be
completed.
All the segments on the display will light up. Press enter to continue.

6
Changing Keypad
NOTE: Do not service with power to the instrument!
1. Remove the battery cover.
2. Using a Phillips screwdriver, remove the two screws in the battery compartment
and the two screws near the strap opening.
3. Lift the zif socket labeled „Keypad“ and remove the keypad cable.
4. Remove the keypad overlay and membrane switch from the cover.
Keypad zif & cable
PT_001.JPG
PT_002.JPG
screws
Keypad zif &cable

7
5. Place the new keypad membranes on the cover (outline first followed by the
keypad), feeding the cable through the slot.
6. Place the cable back into the appropriate zif socket.
7. Place the overlay on top of the membrane keypad.
8. Before sealing, plug in and confirm display and keypad are working.
PT_003.JPG
PT_004.JPG

8
9. Place silicon drops in four places (both top corners and the bend on both sides).
10.Place the cover on the base.
11.Replace all four screws.
PT_002.JPG

9
Changing Display
NOTE: Do not service with power to the instrument!
1. Remove the Battery Cover.
2. Using a Phillips screwdriver, remove the two screws in the battery compartment
and the two screws near the strap opening
3. Lift the zif socket labeled „Keypad“ and remove the keypad cable.
4. Lift the zif socket labeled „Display“ and remove the display cable.
PT_001.JPG
PT_002.JPG
screws
Disply zif &cable
Keybad zif and cable

10
5. Remove the two screws and washers holding the display with PCB on the cover.
6. Clean, and make dust free, the display and the cover.
7. Reassemble by following steps 3-5 in reverse order.
PT_005.JPG
screws
PT_006.JPG