Question

A pyranometer is a............... measuring instrument, commonly used for climate research or monitoring weather performance.

• A. solar irradiance
• B. atmospheric pressure
• C. wind speed
• D. cloud celling

Answer 1

Answer:

A. solar irradiance

• A pyranometer is an instrument designed to measure global solar irradiance.

• Global solar irradiance refers to the total solar radiation received on a horizontal surface from the sun and the surrounding atmosphere.

• This includes both direct solar radiation (sunlight coming directly from the sun's disk) and diffuse solar radiation (sunlight scattered by the atmosphere, clouds, and other particles).

How it works (Basic Principle):

• Most pyranometers operate on the principle of a thermocouple or thermoelectric generator.

• The instrument typically has a black-coated surface that absorbs solar radiation, causing its temperature to rise.

• This temperature difference between the absorbing surface and a reference temperature is converted into an electrical voltage by the thermocouple.

• The voltage output is directly proportional to the intensity of the solar radiation received.