This is a portable and convenient instrument， which can detect temperature， humidity， wet bulb & dew point temperature. It is suitable to be used in the field of laboratory research， industrial， engineer， and other professional circumstance etc. With white backlight， you can use it to detect temperature & humidity at night or dark place.Features:Based on SCM design， fast response time and sampling: 2.5 times/second.With temperature & humidity semiconductor sensor， high in accuracy.LCD display with white backlight， clear to see temperature， humidity， wet bulb & dew point temperature， maximum & minimum value.Dual display of temperature and humidity， easy to exchange between ℃ and ℉.Other functions: data hold， auto power off after 15 minutes， low power indication.The vane part is spinning for better measurement.Can be widely used in the field of laboratory， industrial， engineer， construction and other professional circumstance etc.Note:1.Never put the sensor in the liquid or under the sun.2.You can press backlight button for 2-3 sec.to turn it on.Specifications:Display: LCD Display with BacklightSensor Type: Temperature & Humidity Semiconductor SensorSampling: 2.5 times/secondHumidity Measurement Range: 0%-100%RHTemperature Measurement Range: -30℃ to 100 ℃(-22℉ to 212℉)Resolution: 0.01%RH， 0.01℃/℉Humidity Accuracy: +/-2%RH (at 25℃， 20-80%RH); +/-2.5% (at other ranges)Working Conditions: 0℃ to 40 ℃(32℉ to 104℉); <80%RH non-condensingPower Supply: Standard 9V Battery， NEDA 1604 or 6F22 Battery (Not Included)Item Size: 22.5 * 5.3 * 3.3cm / 8.86 * 2.09 * 1.3inItem Weight: 151.5g / 5.34ozPackage Size: 29 * 15 * 5.5cm / 11.42 * 5.91 * 2.17inPackage Weight: 218.5g / 7.71ozPackage List:1 * Thermometer Hygrometer1 * User Manual1 * Package Bag