One element of lie detection, as carried out by lie detecting machines, is the measurement of galvanic skin response–how sweaty the questioned person becomes. This simple electronics project recreates that measure right in your workshop.

At Make Magazine they’ve shared a guide to building your own galvanic skin response tester. It’s not a full lie detector (nor are lie detectors even as accurate as Hollywood would have us believe); none the less it’s a fun little project and a great way to learn about physiology and electronics at the same time. Watch the video above to see how they build and test it, then hit up the link below for detailed instructions.

The Truth Meter [Make Projects]