The Extech RH520A-240-NIST digital hygrometer and thermometer combines precise humidity and temperature monitoring with data logging capabilities. It features a dual graphical LCD display, measuring humidity from 10% to 95% RH and temperature from -20.0°F to 140.0°F, with an accuracy of ±3% RH and ±1.8°F/1°C. Equipped with internal memory for 49,000 data points and RS-232 connectivity, it is ideal for labs, museums, and maintenance tasks. The device offers flexible mounting options, adjustable display resolutions, and alarms for high/low humidity and temperature, making it excellent for environmental monitoring and data trend analysis.