a moisture testing device having various applications including the testing of moisture in the thermal insulation of insulated pipe , the device having a readout and related components connected to a detector assembly which is pivotally mounted at the end of an adjustable pole . the detector assembly utilizes the principle of neutron back scatter or neutron moderation which is known for measuring water and hydrogen , but it is designed as a highly efficient screening device which can for example test thousands of feet of pipe in a day .