Basically, the device works reliably. Calibration, below 90 degrees keep on a wall and you have meaningful results. However, there is a real stumbling block for me. If the battery is new - everything was great. After an estimated 50 measurements following problem occurred. On a wet basement wall (brickwork) a value was changed from "70" is displayed, which should also correspond to the reality. If you switch now a backlight falls below the value of "40" from. Lights and the value is right again. Multiple tried with new battery again properly. Unfortunately, the device does not display the battery voltage, so caution is already on offer. The specified max. 4 cm measuring depth seem to agree, the operation is simple. Therefore nevertheless 4 stars.
