Grounding Tester

A small probe tester for earthing gear. Take the cap off, touch both probes to the mat, and if the light comes on the mat is conducting. Sixteen dollars, three LR41 batteries already in it.

Buy this if you own any grounding product at all, because without it you are taking the whole thing on faith. A conductive layer can wear through or stop conducting with no outward sign whatsoever, and there is no way to tell by looking at it.

Be precise about what it does, because two different tests get muddled together. Both probes on the mat surface tests the mat. One probe on the mat and one on the ground pin of the plug tests the mat and the cord together, which is the version worth doing, because a cord can fail internally while looking perfect. Neither test tells you the outlet is actually bonded to earth, and in older houses a surprising number are not: the third hole is there, the wire behind it is missing. For that you want a three-light outlet tester from any hardware store, about ten dollars. Between the two you have ruled out the common failures.

It is not glamorous and it is the most useful thing on this shelf.

Good to Know

Comes with 3 LR41 batteries pre-installed. Works on grounding mats, sheets and wristbands. Continuity only; it does not verify the outlet.

Try It With

The green grounding mat or the King leather mat. More in wellness.