Testo 0560 0540 540 lux meter illumination measuring device testo 0560 0540 p the 540 lux meter from testo can be used to measure both artificial and natural light and provides you with a quick and easy means of assessing lighting conditions in the workplace the light sensor is modelled on the spectral sensitivity of the human eye and is ideal for use in a variety of applications p p what s in the box br lux meter br calibration certificate br protective cap br 2x aaa batteries p testo