The HI 9565 by Hanna Instruments® is a digital, portable thermo hygrometers which isdesigned to provide excellent performance in harsh environments and poorly lit areas. A microchip built into the RH probe, HI 70602, can store calibration data. When the probe is connected to another hygrometer, the microchip transfers the stored calibration data and eliminates the need to recalibrate the instrument.In addition to RH and temperature, HI 9565 will display the dew point with the press of a button. The dew point indicates the presence of water vapor in the air at a given temperature. With this feature HI 9565 permits useful and rapid environmental monitoring where a controlled microclimate is necessary, like greenhouses, museums, clean rooms and laboratories. This relative humidity meter features Auto-Off after 20 minutes of inactivity, temperature readings in Celsius and Fahrenheit, and on-line help to indicate anomalies and direct procedures. Hanna #: HI 9565. Range (RH): 20.0 to 95.0% Range (Temperature): 0.0 to 60.0°C (32 to 140°F) Range (Dew Point): -20.0 to 60.0°C / -4.0 to 140.0°FResolution (RH): 0.1% RH Resolution (Temperature): 0.1°C / 0.1°FResolution (Dew Point): 0.1°C / 0.1°FAccuracy (RH): ±3% RH (50 to 85% RH) / ±4% RH (outside) Accuracy (Temperature): ±0.5°C / ±1°FAccuracy (Dew Point): ±0.5°C / ±1°FProbe: HI 70602 RH combined probe with built-in temperature sensor,microchip and 1 m (3.3') cable (included) Battery Type / Life: 1 x 9V / approx. 250 hours of continuous use; Auto-Off after 20 minutes of non-use Environment: 0 to 60°C (32 to 140°F); RH max 98% non-condensing Dimensions: 164 x 76 x 45 mm (6.5 x 3 x 1.8") Weight: 340 g (12 oz.) HI 9565 is supplied with HI 70602 RH probe, battery, blue protective case and instructions.