SRT-M37-L Luminance Lens Adapter for
VL-37 Iluminance Detector
CT-4501 Illuminance & Luminous Color Detector

A cost effective strategy to perform both illuminance and luminance measurements is to outfit VL-37 series illuminance detectors or CT-4501 series illuminance and color detector with front lens adapters. The luminance adapters limit the field of view of the illuminance detector to enable luminance measurement in cd/m² or fL of large area luminous sources. Or with the CT-4501 luminous color, illuminance and luminance can be measured. The SRT-M37L series front lenses attach to the front of the 37-type and 45-type detector housings using the SRT-M45/37 base mount which fits onto the detector housing and is held in place with set screws. The SRT-M45/37B is internally threaded (M37x1) so that the externally threaded SRT-M37L front lens can be screwed into it. The SRT-M45/37B base mount has an M6 and standard camera (1/4”-20 BSW) threaded hole for tripod or bench post or to fixture the device into an application. Front lenses with 1°, 2°, 5° and 10° are offered. Lens assembly and detector are calibrated in luminance sensitivity. The calibration of luminance in cd/m² or footlamberts (fL) is performed at Gigahertz-Optik’s Calibration Laboratory for Optical Radiation Quantities.