H300 Temperature Humidity Chamber
Page 9
Controlling High Humidity
When the chamber is controlling humidity above 80%RH, there is a limit on how high the humidity inside the
chamber can climb. This limit mostly depends on the temperature inside the chamber. Approximate
maximum humidity limits vs. chamber temperature are shown in Figure 4.
Chamber
Temperature °F
Max Humidity
70°F
100°F
45°F
120°F
95%RH
80%RH
60%RH
Figure 4: Maximum Chamber Humidity vs. Temperature
When operating the chamber below 70°F, some condensation inside the chamber is possible when the
humidity inside the chamber is above 80%RH. As the chamber tries to increase humidity, it pumps warm
vapor into the chamber. At the same time, it tries to control the temperature, causing the temperature
control fins to cool and fall below the dew point. This causes condensation on the fins. Condensation will
not harm the chamber, but will prevent humidity increasing above the limits shown in Figure 4.. Any
condensation can be wiped off with a paper towel.
Make sure not to touch the sensor assembly at the top of the chamber when wiping off condensation.
Watlow EZ-ZONE PM Controllers
The H300 unit uses the Watlow EZ-ZONE PM controllers. The controller User’s Manual has been provided
with the H300 chamber. In general you should not need to reference this manual, unless you are setting up
a profile.
Changing Temperature Units
To change the temperature controller units follow the procedure below:
