Owner's manual

HYGROCONTROL Manual for Type 83 Page - 12 -
results of a measurement of saturated vapour over ice at different
temperatures below zero.
Table 3: Display at 100% RH over Ice at different Temperatures
Temperature (°C) PSF (mbar) PSE (mbar) M (%RH)
0 6,11 6,11 100,0
- 5 4,22 4,02 95,3
-10 2,87 2,60 90,6
-15 1,91 1,66 86,9
-20 1,26 1,03 81,7
-25 0,81 0,64 79,0
-30 0,49 0,37 75,5
PSF = Saturated Vapour Pressure over Chilled Water
PSE = Saturated Vapour Pressure over Ice
M = Relative Humidity displayed by HYGROMESS Instruments.
6.7 Measurements under Pressure or Vacuum
All probes can be used at pressures of 0,9 to 1,3 bar. Only special
probes with a glass feed-through (which predicts SS - 316 tube
material) may be used under pressures of 0,03 to 30 bar. As relative
Humidity is directly proportional to the pressure (for example: increase
of pressure by factor 2 also increases relative Humidity by factor 2,
when temperature and content of water remain constant!) you should
take care of a place with constant pressure values, when mounting
the probe. Be aware that pressure may change, when diameters of
tubes change - and air streams may be turbulent at these places.