SRA01 albedometer is an instrument that measures global and reflected solar radiation and the solar albedo, or solar reflectance. It is composed of two identical second class pyranometers with thermopile sensors, the upfacing one measuring global solar radiation, the downfacing one measuring reflected solar radiation. SRA01 complies with the latest ISO and WMO standards.
Albedo, also called solar reflectance, is defined as the ratio of the reflected to the global radiation. The solar albedo depends on the directional distribution of incoming radiation and on surface properties at ground level. Albedos of typical surfaces range from about 4 % for fresh asphalt, and 15 % for green grass to 90 % for fresh snow.
SRA01 albedometer design
Using SRA01 is easy. The albedometer is composed of two pyranometers, the upfacing one measuring global solar radiation, the downfacing one measuring reflected solar radiation. The irradiance in W/m2 in each direction is calculated by dividing the pyranometer output, a small voltage, by the sensitivity. The sensitivity of both pyranometers, model SR01, is provided on the SRA01 product certificate. The albedo is calculated by dividing the reflected radiation by the global radiation. The working principle and specifications of the pyranometers can be found in the SRA01 manual. SRA01 can be connected directly to commonly used datalogging systems.
Albedometers are used for general meteorological observations, building physics, roof reflectance studies, climate studies and solar collector testing. A common application is for outdoor solar radiation measurements as part of a meteorological station. This application requires horizontal levelling; a bubble level is included. SRA01 is made to fit a ¾ inch NPS mounting tube. SRA01 can be ordered with longer cable and optional sun screens
Applicable instrument-classification standards are ISO 9060 and WMO-No. 8. Calibration is according to ISO 9847 and ASTM G207-11.
Suggested use• agricultural networks
• general meteorological observations
• building physics, roof reflectance studies
Options• longer cable, in multiples of 5 m
• sun screens