Testo 540 portable light meter.
 An indispensable device in the effective control of lighting levels suitable for reading and displaying books, graphic documents and museum pieces.
 HOLD button and min / max values
 Sensor adapted to the spectral sensitivity of the view
 Protective cover for safe storage
 Display light
 Lux probe type: measuring range: 0 ... 99,999 Lux; Accuracy: + 3%; Resolution: 1 lux (0 ... 19,999 Lux) 10Lux (Remaining measuring range)