HD2301
- 12 -
V1.7
Calibrating the points at 33% RH and 11% RH
Repeat the points from 3) to 9) using the saturated salts at 33% RH and 11%
RH.
When completed, unscrew the ring with the cap, and screw the protection grid
back on the sensors. The calibration is now complete.
Important notes:
1)
Do not let hands touch the RH sensor.
2)
The sensor base is in alumina so it could easily break.
3)
During the entire calibration cycle keep the temperature as constant as possible;
plastic materials are poor thermal conductors, therefore some time is needed for
them to reach a thermal equilibrium.
4)
In case no satisfactory results are obtained, check that:
•
the sensor is not faulty, corroded or dirty,
•
the measuring chamber is perfectly closed during calibration,
•
the saturated solutions are not exhausted. A saturated solution at 11% RH or
33% RH is exhausted when there is no more salt inside between the two walls
but only a thick liquid: in this case the chamber cannot reach its saturation
anymore. For the saturated solutions at 75% RH, check that the salt is not dry
(crystallized): in order to reach the saturation, it needs to be wet.
5)
Storage of the saturated solutions: the saturated solutions must be stored in a
dark environment at a constant temperature of about 20 °C with the container well
closed inside a dry room.
Temp
Lithium
Magnesium
Sodium
°C
Chloride
Chloride
Chloride
0
11.23 ± 0.54
33.66 ± 0.33
75.51 ± 0.34
5
11.26 ± 0.47
33.60 ± 0.28
75.65 ± 0.27
10
11.29 ± 0.41
33.47 ± 0.24
75.67 ± 0.22
15
11.30 ± 0.35
33.30 ± 0.21
75.61 ± 0.18
20
11.31 ± 0.31
33.07 ± 0.18
75.47 ± 0.14
25
11.30 ± 0.27
32.78 ± 0.16
75.29 ± 0.12
30
11.28 ± 0.24
32.44 ± 0.14
75.09 ± 0.11
35
11.25 ± 0.22
32.05 ± 0.13
74.87 ± 0.12
40
11.21 ± 0.21
31.60 ± 0.13
74.68 ± 0.13
45
11.16 ± 0.21
31.10 ± 0.13
74.52 ± 0.16
50
11.10 ± 0.22
30.54 ± 0.14
74.43 ± 0.19
55
11.03 ± 0.23
29.93 ± 0.16
74.41 ± 0.24
60
10.95 ± 0.26
29.26 ± 0.18
74.50 ± 0.30
65
10.86 ± 0.29
28.54 ± 0.21
74.71 ± 0.37
70
10.75 ± 0.33
27.77 ± 0.25
75.06 ± 0.45
75
10.64 ± 0.38
26.94 ± 0.29
75.58 ± 0.55
80
10.51 ± 0.44
26.05 ± 0.34
76.29 ± 0.65
85
10.38 ± 0.51
25.11 ± 0.39
90
10.23 ± 0.59
24.12 ± 0.46
95
10.07 ± 0.67
23.07 ± 0.52
100
9.90 ± 0.77
21.97 ± 0.60