Apogee Pyranometer

A pyranometer is an instrument used to measure the amount of solar radiation (power) the sun produces in a specific location.

Apogee Pyranometer Sensor

Apogee Pyranometer Sensor


These devices are compact and easy to use for surveying solar radiation anywhere. Pyranometers are typically used in conjunction with a multimeter in order for a reading to be obtained.

Pyranometer with multimeter

Pyranometer with multimeter.


The ability to measure the intensity of solar radiation for a certain area can be used to: design photovoltaic systems (solar panels), establish greenhouse locations, predict insulation requirements (for structures),etc. Essentially a pyranometer can be used whenever solar intensity data is required.


The three types of solar radiation are measured:

  • Direct
  • Diffuse horizontal
  • Global horizontal

Direct and diffuse radiation measurements combined should add up to the global horizontal measurement (total radiation). The pictures below refer to the typical set up of styles measuring these three components of solar intensity. A pyranometers output is in millivolts and each instrument is calibrated to measure the power emitted by the sun in Watts/meter². Each pyranometer is calibrated and a specific calibration constant (numerical value) is given to accurately calculate the output in watts. With this in mind a multimeter (set to 300Mv) is connected to the pyranometer and the reading is multiplied by the calibration value to give a final value in watts/m². Most solar panel designers assume a maximum average of 1000watts/m² can be obtained anywhere on the planet.

Global horizontal reading with pyranometer Diffuse horizontal reading with pyranometer

Global horizontal reading | Diffuse horizontal reading

Direct radiation with pyranometer

Direct reading



OPERATING ENVIRONMENT: -40 to 55 °C;  0 to 100% relative humidity, outdoor use, submersible.

OUTPUT: 0.25 mV per W m-2 (calibration  provided).

RANGE: 0 to 2000 W m-2 (full sunlight =1000 W m-2)

POWER: Self powered

Spectral response of pyranometer

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