Programmable Hygrometer/ Thermometer measures from 10.0 to 95.0% relative humidity and temperature from 0.0 to 199.9°F and -18.0 to 93.0°C. Simultaneously displays both temperature and relative humidity on its dual 1-1/8 inch LCD display. Precision thermistor offers a temperature accuracy of ±1°C between 32 and 104.0°C, otherwise ±2°C, and a resolution of 0.1°. Easily switch between Fahrenheit and Celsius readings. An audible click confirms each key entry. Microprocessor-based design provides unparalleled accuracy. Makes changing probes and maintaining accuracy easier than ever before. Resistive polymer film sensor provides humidity readings with an accuracy of ±2% mid-range to ±4% elsewhere. Humidity resolution is 0.1% RH. An individually serial-numbered Traceable Certificate is supplied to indicate instrument traceability to standards provided by NIST. At the touch of a button, recall the minimum and maximum humidity and temperature readings captured during any time period. A special HOLD button permits "freezing" the display to capture readings. Perfect when results must be recorded at routine intervals. Also features an auto-off function to save battery life (selectable). Unit is equipped with an RS-232 output socket for transferring data to a computer. Handsome, dual-tone ABS case is both lightweight (10.7 ounces) and rugged for extreme field or lab use. Comes complete with probe/cable, operation manual, Traceable® Certificate, hard plastic carrying case and 9-volt battery for 100 hours of continuous use. Size is 7-1/8 x 2-3/4 x 1-1/4. Probe is 8-1/2 inches long with 0.7-inch diameter and a 3-foot cable.