Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 174)

IM 11M12A01-05E 12-11
12. Troubleshooting
12.3.3 Measurements Sometimes Show Abnormal Values
<Causes and Countermeasures>
(1) Noise may be mixing in with the converter from the detector output wiring.
Check whether the converter and detector are securely grounded.
Check whether or not the signal wiring is laid along other power cords.
(2) The converter may be affected by noise from the power supply.
Check whether or not the converter power is supplied from the same outlet, switch,
or breaker as other power machines and equipment.
(3) Poor wiring contact
If there is poor contact in the wiring, the sensor voltage or thermocouple emf
(voltage) may vary due to vibration or other factors.
Check whether or not there are loose points in the wiring connections or loose
crimping (caulking) at the crimp-on terminal lugs.
(4) There may be a crack in the sensor or leakage at the sensor-mounting portion.
If the indication of the measured value varies in synchronization with the pressure
change in the furnace, check whether or not there is a crack in the sensor or whether
the sensor flange is sticking tightly to the probe-attaching face with the metal O-ring
squeezed.
(5) There may be leakage in the calibration gas tubing
In the case of a negative process inner pressure, if the indication of the measured
value varies with the pressure change in the furnace, check whether or not there is
leakage in the calibration gas tubing.