13.6.3. The measured value is too low (i.e. too dry)
13.6.4. The measured value varies significantly
121
15.6.3. The measured value is too low (i.e. too dry)
15.6.4. The measured value varies significantly
126
Cause
Solution
The pressure at the measuring point
is lower than the system pressure.
The pressure dew point is therefore
drier at the sensor.
Eliminate the cause of pressure loss. Change the position of the taps.
Expanded air is being measured.
When the probe is installed in the pressurized area the pressure dew point (dew
point under pressure) is measured. When it is installed under normal atmospheric
conditions (ambient pressure) or at an outlet of compressed-air system (expanded
air), the atmospheric dew point is measured. The dew point is significantly lower
following expansion, i.e. the air is dryer.
The sensor must be recalibrated.
Send the probe to the manufacturer for recalibration.
The sensor is damaged.
Send the probe to the manufacturer to be repaired.
Cause
Solution
The pressure at the measuring point
is not constant.
Eliminate the cause of pressure loss or establish constant pressure and airflow
conditions.
The airflow conditions are highly
variable; there is stagnant air.
Dry out the system. Allow air to flow out of the furthest sampling location.
There is water in the system. There is
back diffusion where there is
stagnant air.
Dry out the system. Allow air to flow out of the furthest sampling location.
The measured value at the measuring
point is becoming increasingly lower
(dryer).
In the case of a newly installed measuring system or portable measurement: The
measured value has not yet settled. Particularly in the case of low dew point
values, it can take 60 minutes or longer until the test line, test chamber and sinter
protection cap are at equilibrium.
Following a moisture ingress:
This is normal behavior, since the system needs to dry out again after the moisture
ingress. The drying time is dependent on many parameters - inter alia the volume
of air extracted and the air flow - and can take several days (especially for low
dew point values).
The temperature is too high when the
measuring chamber is connected to
the compressed-air line, and then
rapidly falls until the actual value is
reached.
The behavior is in keeping with the laws of physics; the abrupt rise in pressure
causes compression heat to be generated, which is immediately recorded by the
temperature sensor. However, this rapidly levels off again.
Please observe the stabilization time.
15.6.3. The measured value is too low (i.e. too dry)
15.6.4. The measured value varies significantly
126
Cause
Solution
The pressure at the measuring point
is lower than the system pressure.
The pressure dew point is therefore
drier at the sensor.
Eliminate the cause of pressure loss. Change the position of the taps.
Expanded air is being measured.
When the probe is installed in the pressurized area the pressure dew point (dew
point under pressure) is measured. When it is installed under normal atmospheric
conditions (ambient pressure) or at an outlet of compressed-air system (expanded
air), the atmospheric dew point is measured. The dew point is significantly lower
following expansion, i.e. the air is dryer.
The sensor must be recalibrated.
Send the probe to the manufacturer for recalibration.
The sensor is damaged.
Send the probe to the manufacturer to be repaired.
Cause
Solution
The pressure at the measuring point
is not constant.
Eliminate the cause of pressure loss or establish constant pressure and airflow
conditions.
The airflow conditions are highly
variable; there is stagnant air.
Dry out the system. Allow air to flow out of the furthest sampling location.
There is water in the system. There is
back diffusion where there is
stagnant air.
Dry out the system. Allow air to flow out of the furthest sampling location.
The measured value at the measuring
point is becoming increasingly lower
(dryer).
In the case of a newly installed measuring system or portable measurement: The
measured value has not yet settled. Particularly in the case of low dew point
values, it can take 60 minutes or longer until the test line, test chamber and sinter
protection cap are at equilibrium.
Following a moisture ingress:
This is normal behavior, since the system needs to dry out again after the moisture
ingress. The drying time is dependent on many parameters - inter alia the volume
of air extracted and the air flow - and can take several days (especially for low
dew point values).
The temperature is too high when the
measuring chamber is connected to
the compressed-air line, and then
rapidly falls until the actual value is
reached.
The behavior is in keeping with the laws of physics; the abrupt rise in pressure
causes compression heat to be generated, which is immediately recorded by the
temperature sensor. However, this rapidly levels off again.
Please observe the stabilization time.
Summary of Contents for TPK 21 LT
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Page 115: ...109 13 APPENDIX...
Page 122: ...13 5 1 Connecting optional accessories 116 15 5 1 Connecting optional accessories 120 DC 24 V...
