The FLIR MR40 moisture meter identifies moisture content by displaying measurements on an LCD display and by giving an audible indication of the measured range. Its small size and built-in 40 lumen flashlight allows this meter to take readings from materials located in dark or hard to reach areas.

The meter quantifies moisture content by passing a small electrical current between the pins when inserted into the material to be measured. The amount of electrical resistance correlates to the amount of moisture in the material. When used in combination with a thermal camera it can confirm whether a cold spot identified in the thermal image is moisture and measure the severity of the problem.