Solar Radiation Sensors

An Albedometer is a device that measures the reflectivity of a surface. It emits a beam of light towards a surface at a specific angle and the light that is reflected back is then measured by a sensor that calculates the albedo of the surface based on the ratio of reflected to incident light.

A Pyranometer is a device that measures solar irradiance from a hemispherical field of view incident on a flat surface. The global irradiance includes direct sunlight and diffuse sunlight. Irradiance is the radiant flux received by a surface per unit area.

Pyrgeometers are devices that measure longwave radiation. As the name suggests, this is a radiation with long wavelengths, more specifically called far-infra-red radiation that is typically between 3 μm to 1,000 μm within the infrared range of electromagnetic radiation.

A Pyrheliometer is a device that measures the solar irradiance coming directly from the sun itself. This type of irradiance is also called ‘direct normal irradiance’ (DNI).

A Net Radiometer is a device that measures the difference between incoming and outgoing radiation from a surface, also known as net radiation. It is useful for measuring direct incoming shortwave radiation, reflected shortwave radiation, diffused long wave (infra-red) radiation against outgoing long-wave infrared radiation and surface-reflected short-wave radiation.