Includes analog output and fast/slow response feature The Extech 401025-NIST is a Foot Candle/Lux Meter which measures light level to 5000FC (foot-candles) and 50,000 Lux with a 5% accuracy using a precision photo diode and color correction filter. Meter features fast/slow response time and an analog output (1mV per count) for capturing readings to a recorder. With NIST Calibration.