Review on 🔍 GemRed Digital Protractor Inclinometer with Finder by Justin Hill

Always enabled in absolute mode (digital levels). Pressing the ZERO button turns it into a relative goniometer. I've verified this with a reversal test on a flat plate, on some 123 block machines and on a home-built angle table ranging from 0 to 2.5 degrees. Readings from the base are generally self-consistent and repeatable to within 0.1 degrees, but rotating left and right shows 89.9 one way and 89.8 the other instead of 90.0 and rotating the base from 0.0 to the exact angle of 90° from the 123 block shows 89.9 degrees. If you rotate more than 90.0 degrees, the numbers on the display will flip upside down, then it will start counting down again, so it will read 0.0 (+/- 0.1) when it's exactly upside down. When leveling close to zero, it sometimes jumps repeatedly between +0.1 and -0.1 (missing 0.0) even with slow and slight angle changes, but then 0.0 appears after a minute. He may need to stand in an upright position on the base (not lying on his back) for a minute or more before taking the measurement. Only one edge (base) is magnetized. Has a reliable coupling with thick steel surfaces. It's not that strong but only supports its weight on a thin piece of vertical sheet metal like the edge of my range hood, even if that surface doesn't cover the full width of the base (see photo). One AAA battery included. The backlight turns off after 30 seconds of no movement, but the numbers continue to appear on the LCD. A simple movement turns the backlight back on. It turns off completely after standing for 5 minutes.