TPS easyCHEM 770, Manual

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Section 7 – Troubleshooting
42
7.4 pH Troubleshooting
Symptom Possible Causes Remedy
Unit fails to calibrate,
even with new probe. Calibration settings outside of
allowable limits due to
previous failed calibration. Reset the unit. See section 6.6.
1 Point calibration fails
(Asymmetry is greater
than +/-1.00 pH). Reference junction blocked. Clean reference junction as per
instructions supplied with the electrode.
2 Point calibration fails
(Slope is less than
85.0%). 1. Glass bulb not clean.
2. Electrode is aged.
3. Connector is damp.
4. Buffers are inaccurate.
Clean glass bulb as per instructions
supplied with the electrode.
Attempt rejuvenation, as per
instructions supplied with the electrode.
If not successful, replace electrode.
Dry in a warm place.
Replace buffers.
Unstable readings. 1. Reference junction
blocked.
2. Glass bulb not clean.
3. Bubble in glass bulb.
4. Faulty connection to
meter.
5. Reference junction not
immersed.
Clean reference junction as per
instructions supplied with the electrode.
Clean glass bulb as per instructions
supplied with the electrode.
Flick the electrode to remove bubble.
Check connectors. Replace if
necessary.
Ensure that the bulb AND the reference
junction are fully immersed as per
diagram in section 5.2.1.
Inaccurate readings,
even when calibration is
successful. Reference junction blocked. Clean reference junction as per
instructions supplied with the electrode.
Displays 7.00 for all
solutions. Electrical short in connector. 1. Check connector. Replace if
necessary.
2. Replace electrode.
Displays 4-5 pH for all
solutions. Glass bulb or internal stem
cracked. Replace electrode.
7.5 Temperature Troubleshooting
Symptom Possible Causes Remedy
Temperature inaccurate
and cannot be calibrated. 1. Faulty connector.
2. Faulty ORP/Temperature
sensor.
Check the connector and replace if
necessary.
Fit new ORP/Temperature sensor.
Displays “ OVR
O
c ” when
temperature probe
plugged in.
1. Faulty ORP/Temperature
socket.
2. Faulty ORP/Temperature
sensor.
Return the instrument to the TPS
factory for service.
Fit new ORP/Temperature sensor.
7.6 Instrument firmware version number
If you need to phone or fax TPS for any further technical assistance, the firmware version number
and serial number of your
easyCHEM 770 may help us to assist you. The version and serial
numbers are displayed by the easyCHEM 770 at turn-on. The firmware version is “V1.1” and the
serial number is “ S1234 ” in the example below…
easyCHEM 770
V1.1 S1234