The Amprobe THWD-10 relative humidity (RH) and temperature meter simultaneously measures relative humidity, dew point, and wet- and dry-bulb temperature using two temperature sensors (K-type thermocouple and thermistor) that provide a range of dual-scale temperature readings, and is used for HVAC, indoor air quality, and environmental applications. The K-type thermocouple sensor measures temperatures from -50 to 1,832 degrees F (-50 to 1,000 degrees C), and has a resolution of 0.2 degrees F (0.1 degrees C). The thermistor temperature sensor has a temperature range from 32 to 140 degrees F (0 to 60 degrees C), and has a resolution of 0.1 degrees F and C. The meter has minimum, maximum, average, and hold functions for recording data, and relative zero functionality stores reference points. It requires four AAA batteries (included), and includes, a k-type thermocouple, a white box and instructions.Specifications K-type thermocouple temperature accuracy (operating temperatures 64 to 82 degrees F) For one year (not including thermocouple error): for temperatures -50 to 1,832 degrees F, accuracy is + or – (0.1 percent of reading + 2 degrees F; for temperatures -58 to -328 degrees F, accuracy is + or – (0.05 percent of reading + 1.4 degrees F) K-type thermocouple temperature accuracy (operating temperatures 18 to 28 degrees C) For one year (not including thermocouple error): for temperatures -50 to 1000 degrees C, accuracy is + or – 0.1 percent of reading + 1 degree C Thermistor temperature accuracy (degrees F) For temperatures 32 to 50 degrees F, accuracy is + or – 4 degrees F, for temperatures 50 to 113 degrees F, accuracy is + or – 1 degree F, for temperatures 113 to 140 degrees F, accuracy is + or – 4 degrees F Thermistor temperature accuracy (degrees C) For temperatures 0 to 10 degrees C, accuracy is + or – 2 degrees C, for temperatures 10 to 45 degrees C, accuracy is + or – 0.5 degrees C, for temperatures 45 to 60 degrees C, accuracy is + or – 2 degrees C RH accuracy + or – 2.5 percent at 77 degrees F (25 degrees C) and 10 to 90 percent RH, and + or – 5 percent at 77 degrees F (25 degrees C) and 0 to 10 percent RH RH sensor response time (90 percent of total range) 60 seconds typical Sensor hysteresis (excursion of 10 percent to 90 percent to 10 percent) + or – 1 percent RH typical Wireless frequency 910 to 920 megahertz, low current consumption less than 1 milliamp (mA), transmitting distance up to 25 meters away without magnetic interference Operating environment at less than 80 percent relative humidity 32 to 122 degrees F (0 to 50 degrees C) Storage environment (with battery removed) at less than 70 percent relative humidity -4 to 140 degrees F (-20 to 60 degrees C) Dimensions 9.5 x 6.22 x 3 inches (241.3 x 157.98 x 76.2 mm) (H x W x D) Weight Approximately .67 lb. (304g), including batteries
H is height, the vertical distance from lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back. A thermohygrometer is a combination thermometer to measure temperature, and hygrometer to measure humidity. It monitors relative humidity and temperature in lab, office, home, and greenhouse applications.

Amprobe THWD-10 Temperature and Relative Humidity Meter uses the Vinnic Alkaline Battery AAA.

This device use the following battery:
	Vinnic Alkaline Battery AAA Buy for $.45