3 Instruments Used to Measure Solar Power

To measure solar radiation, you need a radiometer. There are numerous types of radiometers that climatologists, as well as meteorologists, use. The ideal type of instrument to measure solar power depends on the type of solar radiation you intend to measure. Here are the three instruments used:

1. Pyranometer

This is the commonly used instrument to measure hemispherical solar irradiance. That is broadband solar radiation. This instrument does well in a 180-degree field of view.

A standard type pyranometer has thermopile sensors behind a glass dome. It is easy to operate since it does not rely on any power. The sensors absorb the radiation on the field, and based on the radiation it encounters, it emits a proportional output voltage.

Pyranometers are commonly placed near a solar panel or on top of a solar panel to ensure optimal panel positioning. Thanks to technological advancements, there are digital Pyranometers that are used not only to record but also to analyze the irradiation data.

The digital Pyranometers can output data in a serial form. They are small and can fit onto your palm. Therefore, they are commonly handheld when taking field measurements.

2. Quantum Sensors

Quantum sensors are specialized devices that measure the photosynthetically active radiation; that is, the visible spectrum which photosynthetic organisms can use using a band of solar radiation.

Quantum sensors measure the PPFD- photosynthetic photon flux density from sunlight. This information is useful in agriculture as it helps to choose the location of the farmland. It also helps farm owners maintain grow houses. They are particularly helpful as 89% of US citizens support solar farms.

The applications of the data are wide since the data obtained is also needed in oceanography to calculate oceans sunlight zones. These sensors use photovoltaic technology to generate data.

3. Pyrheliometer

A pyrheliometer works similarly to a pyranometer and measures only the direct beam solar irradiance. Therefore, they are only occasionally used in pyranometer applications.

This instrument is also used to track solar systems and ensure that the entire solar system is aimed towards the sun all the time. Apyrheliometer is often mounted on a tracking system to measure direct beam sunlight.

The sun rays will penetrate the heliometer through its integral lenses. The lens will project the sunlight to a thermocouple which is located within the device. Pyrheliometer is designed to convert thermopile’s small voltage to watts.

Factors to Consider When Choosing Instruments to Measure Solar Power

Here are things to keep in mind when choosing a solar power measuring instrument.

1. Determine What You Would Like to Measure

Now that you know the instruments you can use to measure radiation, you need to be specific about what you are looking to measure. Solar radiation has numerous applications, and each application has a different measuring method.

For example, if you are looking to measure global horizontal irradiation, irradiance in a plane of the array, or on a tilted plane, a pyranometer is the right instrument for you. It is also ideal if you need to measure reflected solar radiation. On the other hand, if you are looking it measure the PPFD to make better farming decisions, quantum sensors will get the job done.

2. Quantum Sensors

Another important consideration is where you intend to install the sensor. For instance, if you choose pyranometers, you should choose sites that are free from any obstructions. This is because their field of view is full hemispherical. Basically, when choosing a site, make sure that you consider the sun’s trajectory throughout the year

3. Properly Install Your Instrument

When it comes to installing your solar power measuring instrument, you want to ensure that it remains aligned or leveled at any time. This helps to ensure accurate and right results.

Pyregeometers and pyranometers have 2 x 5M threads that allow you to mount from below on a 46 mm or 65mm pitch. As for pyrheliometers, they are mounted on a solar tracker on 38 mm tube diameters.

4. Connect to Datalogger

If the instrument you choose has an analog output, then you should connect it to a datalogger or voltmeter. You just need to ensure that the datalogger you choose is of good quality and offers great resolution in a low voltage range.


There is no denying that choosing the right instrument will give you accurate measurements to give you accurate solar radiation data. With this information, we hope that it will be easier for you to select the right instruments for your solar power needs.

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