Sper Scientific 800037 WBGT SD Card Logger reads relative humidity (RH), air temperature (TA), dew point, wet bulb globe temperature (WBGT) and black globe temperature (TG). Also captures sample time and date. RH: Range 5 ~ 95% RH; Res. 0.1; Accuracy > or = 70% RH ± 3% rdg + 1% RH, <70% RH ± 3% RH