AMF03 mounting fixture

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.

An albedometer is an instrument composed of two pyranometers, the upfacing one measuring global solar radiation, the downfacing one measuring reflected solar radiation. You can then derive the solar albedo, or solar reflectance and net solar radiation. Albedometers are increasingly popular in bifacial PV module performance monitoring.

You may use one AMF03 albedometer kit and two model SR30 pyranometers to construct an albedometer of Spectrally Flat Class A, the highest accuracy class according to ISO 9060 (formerly known as ‘secondary standard’). AMF03 may also be combined with model SR15 pyranometers to construct a Spectrally Flat Class B albedometer. The modular design facilitates maintenance and calibration of the pyranometers. By taking the instrument apart you can use normal indoor calibration facilities for instrument calibration. SR30-M2-D1 and SR15 series pyranometers (SR15-A1, SR15-D1 and SR15-D2A2) are supplied with several outputs; analogue millivolts, 4-20 mA current loop and Modbus over RS-485 are the most commonly used. 

AMF03 is easy to use. It allows you to combine two separate SR30-D1 or SR15 series pyranometers creating one SRA30-D1 or SRA15 series albedometer. All you need are two suitable pyranometers and the AMF03 kit. Mounting instructions and a set of hex keys are delivered with AMF03. AMF03 also includes a glare screen.

A glare screen is a metal ring, mounted on the downfacing sensor. At solar elevations of < 5 °, when the sun is just above the horizon, the glare screen prevents that direct solar radiation is measured by the downfacing sensor. This is important, because it would lead to unrealistic albedo measurements. Modern data quality assurance can also attain the data quality by calculating solar elevation and rejecting any data at solar elevations below a certain value, for example < 10 °.

Levelling and mounting may be completed by using ALF01 levelling fixture and CMF01 crossarm mounting fixture to mount the crossarm to a mast.