The Protimeter insulated 'Deep Wall Probes' measure moisture at depth in walls and other structures regardless of surface dampness or contamination. Deep Wall Probes may be used to investigate high readings that were obtained in Search mode and to determine the moisture profile through a structure by increasing the depth of the clearance holes incrementally. In order to take a reading, two clearance holes 6 mm in diameter need to be drilled. The deep wall probes can be utilised with the Protimeter Mini, Surveymaster and MMS instruments.