humimeter RH5 & RH5.1 Operating Manual
Page 18
5.2
Adjustment behaviour of the sensor
In humidity and temperature measurement, several parameters are responsible for the
adjustment behaviour (time until the actual measured value is displayed). The para-
meter responsible for the highest measuring error is a temperature discrepancy
between the sensor resp. the whole measuring instrument and the material being
measured resp. the air.
Therefore, allow your humimeter RH5 to adjust until the displayed temperature corres-
ponds to the actual temperature. The graph below shows how long it takes to adjust
from 20 °C to 30 °C:
When using the sword sensor holder, pay attention to the temperature adjustment
between the sword sensor holder and the sword.
To demonstrate the importance of temperature adjustment, the table below shows the
measuring errors due to a temperature difference between the measuring instrument
and the material being measured of only 1 °C / 1.8 °F, at different ambient tempera-
tures.
10 °C (50 °F)
20 °C (68 °F)
30 °C (86 °F)
10 % r.h.
+/- 0.7 %
+/- 0.6 %
+/- 0.6 %
50 % r.h.
+/- 3.5 %
+/- 3.2 %
+/- 3.0 %
90 % r.h.
+/- 6.3 %
+/- 5.7 %
+/- 5.4 %
At room temperature (20 °C / 68 °F) and an assumed paper moisture value of 50 % r.h.
a temperature difference between the measuring sensor and the material being measu-
red of 1 °C / 1.8 °F causes a measurement error of 3.2 % r.h. A temperature difference
of 3 °C / 5.4 °F would cause a measurement error of more than 10 % relative humidity.