The Surveymaster offers two ways to monitor the moisture content of materials: penetrating pins and non-invasive radio frequencies. Use it to distinguish sub-surface from surface dampness, essential information when diagnosing the extent and cause of a moisture problem. The GE Protimeter Surveymaster moisture meter features a search mode to be used to assess the moisture level beneath the surface of solid walls and floors independently of surface conditions. The nominal depth of the measurement is 3/4 in (19 mm); this depends on the density and other characteristics of the material. When held against the surface, the GE Protimeter Surveymaster moisture meter transmits a signal into the material. The relative moisture level is shown on the digital display and its moisture condition is shown on the accompanying scale of color-coded lights.