CAMAG ADC 2 - Humidity Values in Practice

ADC 2
Instruction Manual, November 2016 Page 38
5. Humidity values in practice
CAMAG has performed several tests using potassium acetate, po-
tassium thiocyanate and sodium chloride. Our experiments
have shown that an average humidity of approx. 47% can
be achieved successfully with potassium thiocyanate. The
humidity values measured by the ADC2 where generally slightly
below the theoretical values: for 47% rH, 44 - 47% rH and for
75% rH, 69 - 73% rH was measured. The reason why the theo-
retical humidity cannot be fully reached is due to the adiabatic
process and the energy balance during aggregate state changes.
A good example is shown in the graphics below:
Fig.16: Measurement of the relative humidity in the ADC2 at start of the humidity con-
trol. Used salt: Potassium thiocyanate, relative humidity in the lab approx. 29%.
Fig.17: Measurement of the temperature in the ADC2 at start of the humidity control.
Used salt: Potassium thiocyanate, temperature in the lab: approx. 23°C. The higher tem-
peratures in the instrument at start are caused by warm up / non equilibrium effects.
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30
32
34
36
38
40
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44
46
48
0 1 2 3 4 5
[% RH]
[Minutes]
RH
°C
22.5
23
23.5
24
24.5
25
0 1 2 3 4 5
[°C]
[Minutes]
RH
°C