The device is calibrated every time you want to use the device and press a button. You can't test anything without spending a few seconds calibrating it first. As soon as you accidentally or intentionally take your finger off the button, it needs to be recalibrated. It works fine, just don't measure with a metal rod right in front of it. I have successfully found several electrical wires between 0.5 and 4 inches long in a (dry)wall. I've also successfully found nails or screws in the walls, 0.5 to 2 inches. I didn't try to look for studs. lets you know if something is wrong with the wiring in the outlet or if the ground connection is working properly.
π CAMWAY 6 Inch Digital Caliper with LCD Display, Electronic Vernier Caliper, 150mm Stainless Steel Feeler Gauge, Plastic Digital Caliper Set for Zero Setting Inside/Outside Diameter, Depth, and Step Measurement Tool
3 Review
π Johnson Level and Tool 400EM-S 12-Inch Heavy Duty Metal Combination Square for Professionals, with Inch/Metric Measurements, Silver - 1 Square
8 Review
TV bracket Kromax DIX-18 black
52 Review
Kapro 307-08-TMS Try And Mitre Layout And Marking Square With Stainless Steel Blade, 8-Inch Length
18 Review