This document discusses solar and terrestrial radiation measurements. It defines solar radiation as visible and near-visible light from the sun between 0.2 to 4.0 μm, and terrestrial radiation as infrared light emitted from the atmosphere. It lists the wavelength ranges for ultraviolet, visible, near-infrared, and infrared radiation. The document then discusses two devices for measuring radiation - the pyranometer, which measures solar irradiance on a surface from 0.3 to 3 μm, and the pyrheliometer, which specifically measures direct beam sunlight and converts the heat to an electrical signal.

2. Solar Radiation Measurements
• Solar radiation is a term used to describe visible and near-visible
(ultraviolet and near-infrared) radiation emitted from the sun.
• The different regions are described by their wavelength range
within the broad band range of 0.20 to 4.0 µm (microns).
• Terrestrial radiation is a term used to describe infrared radiation
emitted from the atmosphere.

3. • The following is a list of the components of solar and
terrestrial radiation and their approximate wavelength
ranges:
• Ultraviolet: 0.20 – 0.39 µm
• Visible: 0.39 – 0.78 µm
• Near-Infrared: 0.78 – 4.00 µm
• Infrared: 4.00 – 100.00 µm

4. MEASURING DEVICES
1.PYRANOMETER
2.PYRHELIOMETER

5. PYRANOMETER
• 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 from
the hemisphere above within a
wavelength range 0.3 μm to 3 μm.

7. PYRANOMETER WORKING PRINCIPLE

13. PYRHELIOMETER
• A pyrheliometer is an instrument for measurement of
direct beam solar irradiance.
• Sunlight enters the instrument through a window and
is directed onto a thermopile which converts heat to
an electrical signal that can be recorded.
• The signal voltage is converted via a formula to
measure watts per square metre.

20. THANK Q