The lux meter hd 450 is suitable in the best way to measure the light in working places offices and public buildings by the use of a precision silicon photodiode and a spectral filter brings precise measuring data with this equipment the hd 450 is best suited by its robust and double transformed housings for the field service in addition stays the device still a data logger at the disposal which stores up to 16 000 measured values continuously and still additionally 99 selected measured valu