Development of a portable reflectometer for field measurements of the specular reflectance of solar mirrors

Conference · Mon Jan 01 04:00:00 EST 1979

OSTI ID:6020984

Freese, J M

Specular reflectance measurements of mirror surfaces used in solar concentrators are needed to determine the effect of accumulated dust on reflectance as well as to detect any permanent degradation of the mirror reflectance. Because it is impractical to remove a mirror from a collector for measurements in the laboratory, a portable reflectometer designed for in-the field measurements of solar mirror materials has been developed. Unlike the standard laboratory bidirectional reflectometer, the portable instrument uses broad band spectral filters, circular apertures rather than slits and accepts a greater beam divergence. However, results obtained with the portable instrument correlated quite well with those of the laboratory reflectometer. The reflectance values of silvered glass, metallized plastic film and polished aluminum were within +-0.005 reflectance units of the values obtained from appropriately averaging reflectance versus wavelength data taken with a laboratory bidirectional reflectometer. The portable instrument has proven useful in monitoring the effects of dirt and weathering on mirror specular reflectance in the field.

• Research Organization: Sandia Labs., Albuquerque, NM (USA)
• DOE Contract Number: EY-76-C-04-0789
• OSTI ID: 6020984
• Report Number(s): SAND-78-2065C; CONF-790541-31
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
141000* -- Solar Collectors & Concentrators
ALUMINIUM
DUSTS
ELEMENTS
FILMS
MEASURING INSTRUMENTS
METALS
MIRRORS
OPTICAL PROPERTIES
PETROCHEMICALS
PETROLEUM PRODUCTS
PHYSICAL PROPERTIES
PLASTICS
REFLECTIVITY
SOLAR CONCENTRATORS
SOLAR REFLECTORS
SURFACE PROPERTIES
TEST FACILITIES
WEATHERING