Chapter 7 – Frequently Asked Questions
Page 68
TestEquity 101H Temperature/Humidity Chamber
Uniformity – Also known as Gradients. This is a measure of variations in temperature at
different locations throughout the chamber interior, at the same time, after stabilization. The
uniformity specification for this chamber is
±
1.0°C or a total of 2°C, when measured at least 2"
away from the chamber interior walls. These specifications are for an empty chamber. The
addition of a test sample may affect the temperature uniformity. For example, an energized test
sample will produce a higher temperature near the sample.
Controller Accuracy – This is the ability of the temperature controller to accurately display a
temperature measurement when compared to a standard. The F4T published accuracy is ±2.0°C.
However, the total measurement accuracy in the chamber includes the RTD sensor accuracy.
RTD sensor accuracy is ±1°C or 0.75% of reading, whichever is greater. Therefore, total system
accuracy over the chamber’s operating range can be as much as ±3°C, although the typical
accuracy is actually better than ±1.0°C.
Can I operate or transport the chamber on its side?
No, the chamber can only be operated or transported in the upright position. Operating or
transporting the chamber on its side may cause permanent damage to the refrigeration system
and void the warranty.
I’m not going to use the chamber for a while. Is there anything I should do to prepare it for
storage?
Perform ALL the steps in the Preventive Maintenance Schedule before placing the chamber into
storage. This will ensure that the chamber will be ready to operate when it is taken out of storage.
If the chamber has a problem and is still under warranty, these problems should be resolved
before being placed into storage, since the warranty period starts from the date of shipment. The
chamber should be stored in a conditioned environment. Do not store it outside or where it will
be subjected to dirt or excessive moisture.
I haven’t used the chamber for a while. Is there anything I should do to prepare it for
operation?
Perform ALL the steps in the Preventive Maintenance Schedule before placing the chamber back
into service. This will ensure that nothing has been damaged and that a leak has not developed.
Can/Should I put a filter in front of the condenser air inlet?
No, TestEquity does not recommend this. Just follow the maintenance procedures and clean the
condenser fins periodically.
How often should I charge the refrigeration system?
This chamber uses a closed-loop refrigeration system. Just like your refrigerator at home, it does
not need periodic charging. If the charge is low, this means that there is a leak. Leaks should be
repaired before recharging.
What kind of Freon does the chamber use?
The word Freon
®
is a DuPont registered trade name for their CFC-based refrigerants and is
incorrectly used as a generic term for refrigerants. TestEquity chambers do not use CFC-based
refrigerants. This system uses refrigerant R-449A.
