You searched for: “soil thermograph”
soil thermograph (s) (noun), soil thermographs (pl)
An instrument that creates a photographic representation of the heat of a designated underground area: A soil thermograph consists of a sensing element that transmits data to a remote recording device.

This entry is located in the following units: soil- + (page 2) thermo-, therm-, thermi-, -thermia, -therm, -thermal, -thermic, -thermias, -thermies, -thermous, -thermy (page 17)