The REED SD-2010 Heat Stress Meter features a datalogger with 2GB SD memory card (optional); Air Temp.: 0 to 50°C; WBGT: 0 to 59°C; Black Globe Temp.: 0 to 80°C; Wet Bulb Temp.: -21.6 to 50.0°C; Dew Point Temp.: -25.3 to 48.9°C; and Humidity Range: 5 to 95% RH. Reed Instruments, www.reedinstruments.com.