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Jim Shaw, EVP of Engineering at Crystal Group, discusses what processes are involved in MIL-STD-810 test for Method 502 Low Temperature.

Video Transcript: Episode 66 – “MIL-STD-810 Test Method 502 Low Temperature”

Hi, Jim Shaw here from Crystal Group.  Going to spend a little bit of time today taking a deeper dive into MIL-STD-810 and specifically today we’re talking about low temperature or Method 502.  And Method 502 is essentially designed to figure out how your equipment, or test how your computer equipment works at lower temperatures. So what are you looking for when you’re doing this test? Why is it imposed on us?

We’re looking for embrittlement of materials or gaskets, binding interfaces, broken glass – that’s one of the common problems. From the electronics standpoint there’s a whole list of things that happen with COTS electronics in super low temperatures. Any crystal oscillators don’t work well. Sometimes the magnetic hysteresis of transformers change their properties. You have startup problems with some of the electronics.

There’s a whole list of things that you need to be looking for when you’re doing low temperature testing. Condensation is another issue but generally from the electronics standpoint it’s really the performance of the circuitry under those extremes, because a lot of those components change their nominal values as you go down. So it’s very important to pick a supplier that uses high quality, industrial, temperature types of components and you got to stick with that.  That’s sort of is our philosophy.

In the low temperature testing that we do here there’s really three test procedures that we look at. We have a storage procedure, then we have an operational procedure, and then there’s one that we don’t really do very often and that’s ease of set up under cold conditions. That’s got to do with arctic mittens and gloves and things like that. And that’s relevant usually from the design standpoint of mil circular connectors but not so much in terms of the testing that we do here.

As a general rule we’ll take a look at either -55C or -65C as a temperature that we’ll test to in a low temperature storage realm. Then we also look at operation, so we’ll go down to -40C for operational testing. There are some things that you have to do to modify COTS equipment to make it perform in those levels so that’s one of the things that we do here at Crystal Group. It’s pretty unique and a lot of our competitors aren’t able or willing to do that kind of thing.

It sets us apart a little bit from that standpoint. That’s the kind of testing that you see in Method 502. There are other specifications out there like DO160 that do something very similar to that. But in effect we follow for the most part MIL-STD-810 and use this Method 502 for the low temperature testing. That’s all I got today. Thanks a lot.

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