Purpose: The instrument is mainly used to determine temperature in the borehole. Lower down the temperature probe into borehole using cable, then you can get temperature-depth curve from controlling unit. The temperature can be used to divide geology sectional surface, determine geothermal gradient, height of concrete surface, and position of water bearing bed. Main technical characteristics 1. Probe: (1) Size: Φ40mm×800mm; (2) Pressure endured: 15 MPa; (3) Measurement range: 5～95℃; (4) Measurement accuracy: ±0.5℃; (5) Time coefficient: <20 s; (6) Insulation resistance: a. Resistance between circuit and instrument shell: >100 MΩ; b. Resistance at moisture environment: not less than 2 MΩ; (Note1: Resistance between circuit and instrument shell is the resistance when the probe is not in the borehole; Resistance at moisture environment is the resistance when dry the instrument after taking it out from borehole. Note2: Measurement voltage should not be more than 30 V); 2. Controlling unit (1) Size: 280×234×138mm; (2) Measurement range: 0～100℃; (3) Resolution: 0.1 ℃; (4) Power supply: 220V, 50 Hz, 4 W;