Sunday, January 18, 2009

About Temperature Testing Chambers

By Peter Brown

Should you need your product to be reliable under any temperature conditions, you will need to test them using a temperature chamber. In the United States there are quite a few manufacturers of this type of equipment.

Other environmental chambers that may be used to test your products would include: AGREE Temperature Chambers HALT Test Chambers Liquid Carbon Dioxide Cooled Chambers Salt Spray Chambers Temperature Humidity Chambers Temperature Plates Altitude Chambers

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

A wide temperature range of -70C to +170C can be achieved by a temperature chamber provided it includes a cascade compressor system (two compressors). A range of -35C to +170C is common for a single stage compressor system.

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.

Most temperature testing includes temperature cycling. This will subject the product being tested to a range of temperatures in a specified time period. Most mechanically cooled temperature chambers have a temperature ramp rate (both up and down) of about 2C per minute (air air temperature) for a specified maximum product load. Should temperature ramp rates beyond this be required, this can be achieved by using larger compressors or CO2 or LN2. It is not unusual for a chamber using larger compressors or CO2/LN2 to achieve temperature ramp rates of up to 15C per minute or more.

Most temperature chambers today include a programmable temperature controller which allows the user to setup the temperature cycle required. Normally this would involve inputting he up and lower temperature limits of the test and also the number of cycles required. The Watlow F4 Programmable Controller is a good example such a temperature Controller. Many manufacturers of temperature chambers include their own controller. Typical options available for controllers include RS-232 Interface, IEEE-488 and extra event outputs which can be used to control the product being tested.

Options offered for temperature chambers are normally the following: Window in the Door Water or air cooled compressors Circular temperature chart recorders Feed-Through Ports Dryer package to remove moist Castors for easy movement of the chamber

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1 comment:

  1. Very Interesting. We are also manufacturer of corrosion salt spray test chambers.
    Know more

    ReplyDelete