Lamtec LT 2 - Page 82

8 Fault Analysis/Trouble-shooting
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8.2.6 D-P test gas calibration too low, not enough gas
Inadequate rise in pressure in preliminary filter during test calibration (<0.5mbar).
Possible causes:
- There is no test gas at the test gas connection of the probe, or inadequate
pre-pressure (0.3bar)
- The shut-off plug valve in the PCB is not open.
- The test gas throttle in the PCB is not open sufficiently.
- The signal from the differential pressure sensor has drifted (recalibrate to “0”).
- Probe preliminary filter cracked or broken (replace)
8.2.7 D-P test gas calibration too high, dirty filter
Excessive rise in pressure in preliminary filter during test gas calibration.
Possible causes:
- Test gas at the probe test gas connection has excessive pre-pressure.
- The signal from the differential pressure sensor has drifted (recalibrate to “0”).
- Probe preliminary filter is dirty (clean)
8.2.8 Insufficient quantity of calibrating gas
An insufficient rise in pressure is discovered during manual offset or test gas
calibration of the KS1-DK.
Possible causes:
- There is no test gas or compressed air at the test gas connection of the probe,
or inadequate pre-pressure (0,3bar)
- The shut-off plug valve in the PCB is not open.
- The test gas throttle in the PCB is not open sufficiently.
- The signal from the differential pressure sensor has drifted (recalibrate to “0”).
- Probe preliminary filter cracked or broken (replace)
8.2.9 Implausible test gas calibration, please repeat
This message occurs when the probe temperature calculated from the probe voltage
and the concentration of gas lies outside the range of 800° - 1200° Kelvin.
Possible causes:
- The O
2
concentration entered under parameter 301 does not correspond to
that of the connected calibrating gas
- Ageing/contaminated sensor? → replace.
- Infiltrated air - check tightness of seals and hose connections.
8.2.10 Analogue input 1/2/3/4 input value too high/too low
The input value at the analogue input in question is outside the permitted range.
Range limits: parameters 574/584/594/604 (min. value) and 578/585/595/605 (max.
value).
The current input value can be read out via parameters 570/580/590/600.
Measures:
- Check wiring → reversed polarity?
- Check source (connected device)
- Faulty input card? → replace