Features Meter accurately determines the Heat Stress level by factoring a combination of humidity, temperature, air movement, and direct solar radiation Uses a capacitance sensor to accurately measure Wet Bulb Globe Temperature (WBGT), Black Globe Temperature (TG), Relative Humidity (%RH), Air Temperature (TA), Wet Bulb (WT) and Dew Point (DEW) Black Globe Temperature (TG) monitors the effects of direct solar radiation on an exposed surface In/Out function displays the WBGT value with or without direct sun exposure WBGT high/low alarm settings Min/Max, Data Hold, Auto Power Off, Low battery indicator Complete with 9V battery and hard carrying case Specifications WBGT - Wet Bulb Globe Temperature (w/o sunlight): 32 to 138°F / 0 to 59°C WBGT - Wet Bulb Globe Temperature (w/sunlight): 32 to 132°F / 0 to 56°C TG - Black Globe Temperature: 32 to 176°F / 0 to 80°C TA - Air Temperature: 32 to 122ºF / 0 to 50ºC Relative Humidity: 1 to 99%RH Dew Point: -31.5 to 120.1°F / -35.3 to 48.9°C Wet Bulb: -6.9 to 122°F / -21.6 to 50°C Dimensions: Meter: 11.8 x 2.8 x 2" (300 x 70 x 50mm) Ball: 2" (50mm) diameter Weight: 7.8oz (220g) w/o battery The HT200 is a Heat Stress WGBT Meter which enables accurate measurements for Wet Bulb Globe Temperature (WGBT), Black Globe Temperature (TG), Humidity (%RH), Air Temperature (TA), Wet Bulb (WT) and Dew Point (DEW). Heat Stress Index measures how hot it feels when humidity is combined with temperature, air movement and radiant heat. Stores up to 50 readings. Comes with 9V battery, carrying case and AC adapter.