The SDL500-NIST records data on an SD card in Excel format. Relative Humidity, Temperature, Dew Point, and Wet Bulb measurements. Adjustable data sampling rate. Stores 99 readings manually and 20M readings via 2G SD card. Type K/J Thermocouple input for high temperature measurements. Large backlit dual LCD display. Record/Recall Min, Max, Data Hold and Auto power off functions. Complete with 6 x AA batteries, SD card, carrying case and Humidity/Temperature probe. Includes certificate traceable to NIST.