Temperature Chambers – Information you Need to Know
March 4th, 2009. Published under Electronics. No Comments.
Temperature testing your product using a temperature chamber can prevent failure in the field and is a necessity today. Mostly these chambers are manufactured in the U.S.A.
Chamber manufacturers produce other types of chambers beside just temperature chambers. These will included: Liquid Carbon Dioxide Cooled Chambers Temperature Humidity Chambers Altitude Chambers Salt Spray Chambers Temperature Plates Liquid Nitrogen Cooled Temperature Chambers AGREE Temperature Chambers Space Simulation Chambers HALT Test Chambers Industrial Ovens
Some of the brands currently available are: Thermotron Tenney Environmental Associated Environmental Blue M Espec Bemco Delta Design Despatch TestEquity ESS Cincinnati Sub Zero Lunaire Ransco Russells Sigma Systems
Every temperature chamber has a specified temperature range. The temperature range of the chamber will depend on the type of refrigeration used to cool it. If the chamber is cooled using Mechanical Refrigeration Compressors, the maximum temperature range is normally -70C to +170C when two compressors in a cascade configuration are included. If on one compressor is used, then the temperature range will most probably be about -35C to +170C.
Beside mechanical compressors, CO2 or LN2 can also be used to cool a chamber. The temperature range obtainable using CO2 or LN2 is normally -70c to +170c.
Since most temperature chambers will be used for cycling the test product through a range of temperatures, a maximum obtainable temperature ramp rate is normally specified. 2c/min is average for a mechanically cooled chamber (with a maximum specified product load. If you require a faster ramp rate, then CO2 or LN2 boost can be added or larger compressors. Temperature ramp rates of up to 15c per minute are obtainable using LN2 or CO2 and/or large mechanical compressors.
Programmable controllers are standard on just about every temperature chamber manufactured today. This enables temperature cycling to be done automatically. A typical programmable controller would be the Watlow F4 controller. Some manufacturers even build their own OEM controllers. Options normally available for programmable controllers are RS-232 Interface and IEEE-488. Sometime extra event outputs can also be provided.
Most temperature chambers are offered with the following optional items: Window in the Door Circular temperature chart recorders Feed-Through Ports Castors for easy movement of the chamber Water or air cooled compressors Dryer package to remove moisture and prevent condensation when chamber is cooled