ATP-Thermo-Hygrometer-with-Dew-Point-ET-931-ATP-ET-931-P-The-ATP-ET-931-Thermo-Hygrometer-with-dew-point-is-a-compact-easy-to-use-robust-instrument-for-fast-repeatable-measurements-of-relative-humidity-temperature-&-dew-point-It-is-ideal-for-single-handed-operation-when-taking-measurements-in-air-stream-Suitable-for-monitoring-air-conditioning-&-heating-system-ducts-controlled-environments-storage-areas-etc-P-ATP-ET-931-Thermo-Hygrometer-with-Dew-Point