Instruments For Measuring Solar Radiation And Sunshine

It is collimates the radiation to determine the beam intensity as a function of incident angle this instrument uses a collimated detector for measuring solar radiation from the sun and from a small portion of the sky around the sun at normal incidence.

Instruments for measuring solar radiation and sunshine.

An alternative method of measuring solar radiation which is less accurate but also less expensive is using a sunshine recorder. Short wave radiation in the wavelength range from 0 3 to 3 μm comes directly from the sun it includes both beam and diffuse components. For a great many years the only instrument for measuring sunshine duration was the campbell. These sunshine recorders also known as campbell stokes recorders measure the number of hours in the day during which the sunshine is above a certain level typically 200 mw cm 2.

The correct exposure of any radiation or sunshine instrument at the observing site is very important. The radiation of sun to the earth s surface consists of 2. The name pyranometer stems from the greek words πῦρ pyr meaning fire and ἄνω ano meaning above sky. In 2003 wmo defined sunshine duration as.

Radiometers for the measurement of sunshine duration. A typical pyranometer does not require. Inter annual monthly mean daily totals solar radiation research laboratory 1986 2000 global trend y 4 3303x 4215 9 r2 0 0034 direct trend y 16 103x 26829. A pyranometer is a type of actinometer used for measuring solar irradiance on a planar surface and it is designed to measure the solar radiation flux density w m from the hemisphere above within a wavelength range 0 3 μm to 3 μm.

Long wave radiation with wavelength 3 μm or longer originates from the sources at near ambient temperatures atmosphere earth surface light collectors other bodies. Ideally the horizon should be level in all directions although the poleward arc is less important for sunshine and direct radiation measurements. The solar radiation reaching the earth is highly variable and depends on the state. Solar radiation and sunshine hours.

For utilization of solar energy through solar collectors measurements of solar radiation and recording of sun shine hours in a day are important to predict the performance of the solar energy devices. Chapter 7 measurement of sunshine duration and solar radiation 7 1 measurement of sunshine duration 7 1 1 definition sunshine duration is the length of time that the ground surface is irradiated by direct solar radiation i e sunlight reaching the earth s surface directly from the sun. Sunshine duration is defined by wmo as the time during which the direct solar radiation exceeds the level of 120 w m2.