Checking The Temperature Input; Incorrect Or Erratic Flow Rate Readings; Erratic Sodium Readings - ABB Navigator 500 Series Operating Instructions Manual

Navigator 500
Sodium analyzer
A.3 Checking the temperature input
1. Check that the wet-section responds to a temperature
input. Disconnect the Pt1000 temperature compensator
leads in the wet-section PCB (see Section 3.4.3, page 15)
and connect a suitable resistance box to the wet-section
PCB inputs.
Note. Resistance boxes have an inherent residual
resistance which may range from a few milliohms up
to 1 ohm. This value must be taken into account when
simulating input levels, as should the overall tolerance
of the resistors within the box.
2. Check that the transmitter displays the correct values as
set on the resistance box – see Table A.3. Incorrect
readings usually indicate an electrical calibration problem.
Temperature °C (°F)
0 (32)
10 (50)
20 (68)
30 (86)
40 (104)
50 (122)
60 (140)
Table A.3 Temperature readings for resistance inputs
3. If the readings checked at step 2 are correct, perform a
resistance check
compensator and confirm the values are as shown in
Table A.3.
4. If the readings are still incorrect, check the connector
block cable connections at the wet-section PCB and their
condition.
76
Resistance 
1000.0
1039.0
1077.9
1116.7
1155.4
1194.0
1232.4
on the Pt1000 temperature
A.4 Incorrect or erratic flow rate readings
Incorrect or erratic flow rate readings may be due to a blockage
in the flowmeter. Stop the flow of sample to the wet-section,
remove the flowmeter and back-flush it with water or air. Re-
connect the flowmeter, start the sample flow and check the flow
reading. If the problem persists a replacement flowmeter may be
required – see page 82.
A.5 Erratic sodium readings
If the sodium reading appears noisy/erratic carry out the
following checks:

check the entrainment of reagent is regular and not
intermittent

check the reagent has not become exhausted – either
check the pH of the sample exiting the flow cell (see
Section A.2, page 75 for ideal pH values) or install a fresh
bottle of reagent solution.

check the flow cell stud terminal (Fig. 2.1, page 6) is
connected securely to a suitable earth (for example, the
earth stud on the transmitter).
Appendix A – Troubleshooting
OI/ASO550–EN Rev. G