The MRH Digital Moisture Meter is a digital, non-destructive moisture and humidity meter for evaluating moisture in buildings and construction materials. It measures moisture content in wood, drywall, masonry, roofing, siding and other materials, and with the optional humidity probe also reads relative humidity, mixing ratio, temperature and dew point. This matters when assessing whether a substrate or environment is dry enough to proceed, for example before laying flooring, since trapped moisture leads to later failure. This product is discontinued.

The meter works on electrical impedance. A low-frequency alternating field is created between conductive rubber electrodes and penetrates the material; the small current that flows is inversely proportional to the material's impedance, from which the instrument derives and displays the moisture content. Because the electrodes sit on the surface, readings are non-destructive, with deep signal penetration to detect elevated moisture through coverings such as ceramic tile, drywall, carpet, vinyl, laminates, wall coverings and roofing membranes. It reads 3 to 40 percent in wood and 0 to 100 on a comparative scale for other materials, with programmable specific gravity from 0.3 to 0.8 to suit most wood species and optimised sensitivity scales for wood, roofing, masonry and drywall. In hygrometer mode the RH probe reads 5 to 98 percent RH. The unit measures 150 x 80 x 35mm.

The MRH can be used in accordance with ASTM F2170-02 and ASTM F2420-05, plus BS 5325:2001 and BS 8203:2001, the standards governing relative humidity testing of concrete slabs and the installation of resilient floorcoverings. As a discontinued model, replacement recommendations are available on request. Supplied by BAMR, South Africa's authorised distributor.