- -
40
0
1
2
3
1
8.
Using the
Up
and
Down
arrow keys it is possible to correct the value with respect to the satu-
rated solution at 75.0 proposed by the instrument. The temperature is the one measured by
the Pt100 or TC sensor. To confirm the calibration point you can use the <REL> key or the
<ENTER> key. With the <REL> key the correction is “applied” remaining in the same
screen: the instrument proposes the value measured and compensated in temperature. Use the
<ENTER> key to confirm the value and quit the procedure. The <REL> key is useful when
you want to have confirmation of the correction made or you want to repeat the operation be-
fore concluding.
After the <REL> key has been pressed, the instrument shows the rela-
tive humidity value found: this will be the same as the value of the saturated solution set
or displayed by the instrument (first line of the display) if the probe and the saturated
solution are at 20°C otherwise it will be corrected according to the temperature read.
9.
Take the probe out of the container. Close the container with its cap.
10.
Unscrew the ring nut with the cap, screw on the sensor protection. This operation concludes
calibration and alignment with a specific point of the RH.
Important notes:
1.
Do not touch the RH sensor with your hands
2.
The base of the RH sensor is made of alumina, so it breaks very easily
3.
During the entire calibration cycle, work as much as possible at a constant temperature; plastics
are generally bad heat conductors, so it takes some time for them to reach thermal equilibrium
4.
If satisfactory results are not obtained, check whether:
•
the sensor is faulty or corroded
•
during calibration the measurement chamber was not perfectly closed
•
the saturated solutions used are exhausted. A saturated solution at 11%RH or 33%RH is ex-
hausted when it not longer contains salt between the two walls but only a dense liquid: in
this case the chamber can no longer reach saturation. For saturated solutions at 75%RH
check that the salt is not dry (crystallised): to reach saturation it must be damp.
5.
Storage of the saturated solutions: saturated solutions must be kept, if possible, in the dark at a
constant temperature of around 20°C with the container tightly closed in a dry place.
