Checking The Temperature Input; Incorrect Or Erratic Flow Rate Sensor Readings; Simple Electronic Check - ABB Navigator 550 Operating Instructions Manual

Navigator 500
Hydrazine analyzer
A.2 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. 3.4.2, 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.2. 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.2 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.2.
4. If the readings are still incorrect, check the connector
block cable connections at the wet-section PCB and their
condition.
A.3 Incorrect or erratic flow rate sensor 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 70.
OI/AHM550–EN Rev. A
Resistance 
1000.0
1039.0
1077.9
1116.7
1155.4
1194.0
1232.4
on the Pt1000 temperature
A.4 Simple electronic check
In the unlikely event that a problem is encountered with the
wet-section, use a current (µA) source and a resistance box to
test the transmitter electrical connections.
To perform a simulated calibration proceed as follows:
1. Access the wet-section
Section 3.4.1, page 14.
2. Disconnect the sensor and Pt1000 connections as
follows:
31: +ve Sensor (Blue)
32: – ve Sensor (Red)
33: Pt1000 (Black)
35: Pt1000 (Yellow)
3. Connect the appropriate wires of the current source and
resistance box to TB2 as follows:
current source +ve: 31
current source -ve: 32
Resistance box: 33
Resistance box: 35
4. Set the appropriate resistance value corresponding to the
thermistor resistance at the nominal sample temperature,
for example:
20 °C = 1077.9 
5. Select the nominal calibration value to 80 µg kg
6. Set the current source to 15 µA.
7. Initiate a calibration sequence by pressing the CAL button.
8. After 15 minutes the display reads the selected
concentration value.
9. Check the wet-section range with different µA values. The
relative values are as follows:
µA µg kg
1.875 8.4
3.75 18.7
7.5 39.1
15 80.0
18.75 100.4
Note. When the electronic systems are operating correctly,
the displayed concentration value should be within
± 0.2 µg kg -1 of the selected value.
PCB as described
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in
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