MEASUREMENT OF REGULAR SPECTRAL TRANSMITTANCE OF OPTICAL FILTERS (PO41, 971-977)

The Standards and Calibration Laboratory (SCL) of Hong Kong has recently developed the calibration service of regular spectral transmittance for optical filters. The laboratory's reference 3-element trap detector and a double monochromator are used as the reference system, instead of using a reference transmittance spectrophotometer, to measure the ratio of the transmitted optical signal to the incident optical signal. The calibration range for transmittance is from 0,01 to 1 for optical spectral range from 400 nm to 1000 nm. The best measurement uncertainty is estimated as 0,53 % for transmittance range from 1 to 0,05, which could support the demands in optical filter calibration from the testing and certification industry in Hong Kong.