Dynalab Silicon Pyranometer model No. DWR 8102M uses a Silicon Photovoltaic cell for measurement of incoming SolarRadiation on a flat surface. The response of this sensor is limited to a wavelength band of approx 400 to 1100 Nanometers. However, most of the solar radiation reaching the surface of the earth falls within this wavelength band and if calibrated against a precision blackbody pyranometer this type of pyranometer can be used to acquire reasonably accurate values of incident Solar radiation especially on clear days. For use in studies in Agricultural Meteorology and Solar energy conversion using photo voltaic devices this model is adequate.The sensor is mounted under a milky white diffuser positioned in such a way as to give good cosine response.The device is calibrated against a secondary standard thermopile type pyranometer.