Chapter 9 – Maintenance
Page 76
TestEquity 101H Temperature/Humidity Chamber
How to Verify the Performance
(Controlled humidity mode)
These tests verify the performance of the humidification/dehumidification, electrical controls,
F4T Controller, and air circulation systems. The chamber should meet all published performance
specifications for controlled humidity conditions if all of these tests are successfully passed.
These tests assume that the F4T Controller’s setup and tuning values have not been changed
from the values as shipped from TestEquity. Also, the Limit Alarm high limit must be set to over
+85°C (+100°C would be fine). If the chamber fails any of these tests, it should be removed from
service to prevent further damage until the cause of the problem is determined and resolved.
1.
The chamber interior should be empty and at ambient temperature, approxi23°C.
There must be at least 1 gallon of single-distilled or deionized water in the reservoir.
2.
Set the Temperature Set Point to 85.0°C, and Humidity Set Point to 85.0% RH. Make sure
the Humidity button is OFF and Purge button is OFF. Press the Power button to turn the
chamber ON.
3.
The chamber should heat up to about +80°C and begin controlling (orange PWR bar should
show less than 100%) within approximately 12 minutes.
4.
The chamber temperature should slowly increase and stabilize to +85°C. It should not
overshoot 86.0°C.
5.
Turn the Humidity button ON.
6.
The chamber humidity should begin to increase within approximately 5-10 minutes. When
the humidity reaches 70% RH it should begin controlling (orange PWR bar should show less
than 100%). The humidity will slowly approach 85% RH.
7.
After stabilization at 85%RH for 30 minutes, the chamber temperature should be 85.0°C,
±0.5°C. The humidity should be 85.0% RH, ±2.5% on a short-term basis.
8.
Next, change the Temperature Set Point to 50.0°C. Leave the Humidity Set Point at
85.0% RH
9.
The compressor should turn ON. The humidity will drop at this point.
10.
The chamber should cool down to about 55°C and begin controlling (blue PWR bar should
show less than 100%) within a short time.
11.
The chamber temperature should decrease and stabilize to 50°C. It should NOT undershoot
50°C by more than 1°C. After stabilization for 30 minutes, the chamber temperature should
be 50.0°C ±0.3°C, or a total of 0.6°C. It may take approximately 45 minutes to stabilize at
85.0%, ±2.5% RH.
12.
Next, change Humidity Set Point to 50.0% RH. Leave the Temperature Set Point at 50.0°C.
13.
The chamber humidity should begin to decrease. It may take approximately 45 additional
minutes to stabilize at 50.0%, ±2.5% RH.
14.
This concludes the controlled-humidity chamber performance verification tests.
