Accessoires
Hagner levert een aantal accessoires voor het gebruik met de lichtmeters.
Reflection Reference
De Hagner Reflection Reference is voorzien van een mat wit oppervlak waarvan de reflectie factor nauwkeurig is bepaald. Deze referentie kan gebruikt worden om de reflectie factoren van andere matte oppervlaktes te bepalen.
SA1 Light Intensity Adaptor
The Hagner SA1 intensity adaptor is intended for use with the Hagner S1, S2, S3 and S4 Universal Lightmeters or with the Hagner E2X and E4-X Digital Luxmeter.
The adaptor consists of an array of collinear fixed circular apertures, which effectively prevent stray lighting from the surroundings reaching the detector. Measurement of light intensity and angular light distribution can then be carried out under normal ambient lightning conditions, avoiding thee cost and complication of special darkened lamp and lighting laboratories.
The Hagner SA-2 Image Adaptor
The image screen adaptor SA-2 is designed to measure the background luminance on image screens and similar surfaces. It can also be used for the measurement of luminance, for instance negative viewing tables.
The adaptor consists of a housing (1) of black polyacetale, a black anodised front plate (2) with a measurement aperture (3) normally of 20mm. diameter. (Other apertures are available on request.) The front plate is covered with a black velvet cloth (4) for prevention of scratching: this also prevents ambient light from reaching the measurement aperture so that the adaptor can be used in high ambient lighting. A black plate (6) is fitted to absorb internal reflections.
Close-up lenses for model S3 and S4
Measuring the luminance of small surfaces.
The Hagner Universal Photometer can be provided with close-up lenses for measuring the luminance of small surfaces at short distances, for example text on data terminal screens, without troublesome light loss.
The close-up lenses are available in sets of 3:
- Focal length 500 mm: (2 dioptres)
- Focal length 250 mm: (4 dioptres)
- Focal length 125 mm: (8 dioptres)
Extension Cables
The Hagner External Detectors are normally provided with a two metre flexible lead. When required, extension cables can be used to increase the distance between the detector and the instrument. The Hagner standard extension cables have a length of 5 metres but other lengths can be provided.