VL-3701 Photometric Illuminance Detector
VL-3702 Photometric Illuminance Detector
VL-3704 Photometric Illuminance Detector
VL-3705 Scotopic Illuminance Detector

The VL-37 series Illuminance detectors are compact 20mm high x 37mm diameter detectors with fine CIE and DIN V(λ) matching spectral responsivity. Three different versions with photopic responsivity and one model with scotopic responsivity are available. All detectors are supplied with a diffuser window and shadow ring for cosine response field of view. The 20mm detector height enables ANSI Lumen rating measurement of projectors. The detectors are supplied with a 2m long coaxial cable with selectable –1, -2 or -4 type connector for use with Gigahertz-Optik’s range of optometers. Calibration of illuminance in lux or fc is performed at Gigahertz-Optik’s Calibration Laboratory for Optical Radiation Quantities. The VL-3701 is a high quality detector for the measurement of illuminance. Its specifications satisfy the requirements for lux detector heads according to DIN 5032 Part 7. Class A. The VL-3701’s spectral adaptation to the V(λ) function for daylight vision is better than 3%. The deviation from the cosine function is < 1.5 %. The VL-3702 is a high quality detector for the measurement of illuminance. Its specifications satisfy the requirements for lux detector heads according to DIN 5032 Part 7. Class B. The VL-3702’s spectral adaptation to the V(λ) function for daylight vision is better than 6%. The deviation from the cosine function is < 3 %. The VL-3704 is a cost effective alternative to the VL-3702 detector for applications where less sensitivity is acceptable. It is a high quality detector for the measurement of illuminance. Its specifications satisfy the requirements for lux detector heads according to DIN 5032 Part 7. class B. The VL-3704’s spectral adaptation to the V(λ) function for daylight vision is better than 6%. The deviation from the cosine function is < 3 %. The VL-3705 detector offers a precise scotopic spectral match with an f1 =< 5%. This is within DIN Class B specifications.