The Extech SDL400 records data on an SD card in Excel format. Wide range up to 100 kLux or 10,000 Fc. Cosine and color corrected measurements. Utilizes a precision silicon photodiode and spectral sensitivity filter. Offset button for zero function for relative measurements. Adjustable data sampling rate. Stores 99 readings manually and 20 million readings on a 2G SD card. Type K/J thermocouple input for high temperature measurements. Large backlit LC display. Record/recall min, max, data memory and automatic switch-off.