Relative humidity measurement from 0 to 100anddegree F or anddegree C selectable Relative function monitors humidity & temperature changes Large dual display of RH & temperature Built-in capacitive sensor with protective cover Complete with carrying case battery & wet bulb chart Auto power off Min Max Data Hold The TRH22 uses a precision capacitance sensor to deliver accurate performance with long term stability. This high accuracy instrument measures the full range of relative humidity from 0 to 100 & features an exceptionally wide ambient temperature measurement range from -20anddegree C -4anddegree F to 60anddegree C 140anddegree F. The sensor is mounted on a long shaft extending from the top surface of the unit making probing into duct work & hard to reach areas more easy. The large LCD displays two measurements simultaneously with a full range of display options including Hold Min Max & Relative. The TRH22 is a complete package & comes with soft carrying case sensor cover battery & manual.