7 | Operation and maintenance
GMH 3331
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B-H77.0.01.DB2-1.0
7.3 Relative air humidity measurement adjustment
Due to the natural ageing of the polymer humidity sensor of the TFS 0100E, readjust-
ment the probe at least once annually is recommended in order to guarantee optimal
measurement accuracy. The product can be sent in to the manufacturer for precise re-
adjustment with linear control. A adjustment function is integrated for 2-point local ad-
justment.
7.3.1 General information for adjustment
Automatic calibration
The following humidity measurement standards are permitted for automatic buffer re-
cognition:
Name
Relative air humidity at 20° C
Calibration device
KNO3
93%
---
NaCl
76%
GFN 76
MgCl2
33%
GFN 33
Silica gel
0%
---
The GFN xx adjustment devices are optimised for the application with the TFS 0100E.
Only these humidity measurement standards are recommended in order to obtain the
most exact adjustment possible. Refer to the accompanying instructions for the exact
use and handling.
If a value of > 50% has been selected for adjustment point 1, a value < 50% must be
used for adjustment point 2. If the value for adjustment point 1 is < 50%, the value for
adjustment point 2 must be > 50%.
Manual adjustment
Arbitrary values between 0% and 100% r.H. can be used. However, the difference
between the two values must be at least 40%.
Automatic temperature compensation for the adjustment
The relative air humidity adjusted in the adjustment devices is partly heavily depend-
ent on temperature. When adjustment with the specified adjustment devices , recogni-
tion takes place automatically and this dependency is compensated for automatically.
If adjustment values are entered manually, it must be ensured that the relevant values
are entered for the appropriate temperature.
NOTE
Adjustmentis only possible in the temperature range of 5 °C .. 40 °C.
Permissible sensor deviation
Adjustmentis only possible if the deviation of the humidity sensor is less than approx.
+/- 10% r.H.. If the deviation is greater, the main display of the product shows the error
message
ERR9
for approx. 2s and the secondary display shows the detected humidity
value. Then the stability test restarts.
In this case, please check your humidity standard. If it is correct, it must be assumed
that the sensor no longer functions correctly. Please sent the product to the manufac-
turer for testing.
Stability criterion
– The humidity value does not change by more than 0.5% r.H. within 20s.
