Finding moisture in walls, floors, timber, caravans or boats becomes faster when you can check the material without damaging the surface. GMI 15 plus uses a capacitive measuring method from the rear side of the device, helping users assess moisture distribution, water damage and drying progress by comparing readings with dry reference points.
For everyday field work, the pocket-format indicator keeps operation simple. Select HOL for wood, BET for concrete/screed or rEF for relative measurements, then read the measured value together with the 6-level WET-to-DRY bar rating. The Hold function freezes the current value for readings in awkward locations.
The device supports non-destructive moisture estimation down to approx. 25 mm measuring depth and can detect moisture behind tiles. Its impact-resistant ABS housing, front side ingress protection (IP)65 and long 9 V battery life of more than 2500 hours make it a practical choice for building inspections, leak detection and wood moisture checks.
The device offers selectable curves for wood and concrete/screed, plus a reference curve for high-resolution relative measurements.
Measurement takes place at the insulated rear side. The full rear surface must lie flat on the material for correct readings.
A button freezes the current measured value and shows HLD on the display, supporting measurements in secluded or hard-to-read positions.
Regular zeroing in air supports stable use. The function is activated via the Hold key and checked with the rEF characteristic.
Two displays show the selected material characteristic and measured value, while a bar graph presents the moisture rating.
The optional PW 25 test cube can be used to check accuracy and apply slope correction in the device settings.
