During my engineering career, I’ve had the fortune of working in a comfortable, room-temperature environment. I’ve visited tropical factories where test equipment was being used in 90°F temperatures with 99% humidity, and I could imagine that same equipment being used on a mountaintop laboratory or in a military vehicle where it could get quite cold. While human operators may find these extreme temperatures uncomfortable, we must also consider the effects of these temperatures on the test equipment—and on the device under test.
Temperature Effects on Lithium-Ion Cells
Let’s start with an example of a device under test. In January 2016 (that means winter here in New Jersey), I was involved in some delicate testing work with lithium-ion cells. Our test goal was to very accurately measure the open circuit voltage (OCV) of the cells over a few days. So, we started making measurements in our comfortable laboratory environment...