What Is a Solar Radiation Sensor? Thermopile, Silicon, PAR, PPFD and Spectrum Selection

Solar radiation, illuminance and PAR are all "metering", but the objects and units of measurement are different. Photovoltaics, agricultural photosynthesis and ordinary environmental illumination cannot be replaced with one another by the same indicator.

What is a solar radiation sensor

Solar radiation sensors are used to measure solar radiation energy or light radiation in a specific spectral range. The amount of attention is different for different applications: common total irradiance or direct/scattered radiation for meteorology and photovoltaics, PAR/ PPFD for plant growth, and Lux for general lighting. Before selecting a model, it is necessary to specify the physical quantity and units to be measured.

Thermopile Total Radiation Meter

The thermopile radiometer converts the absorbed solar short-wave radiation into a thermoelectric potential, which has a wide spectral response range and is suitable for total solar radiation, photovoltaic performance evaluation and meteorological research. The NiuBoL TBQ type total radiation meter belongs to the thermopile principle.

Silicon photoelectric radiation sensor

Silicon photovoltaic cells are fast-responsive, low-cost and low-power, suitable for agricultural and general environmental monitoring. However, its spectral response is not completely consistent with the full spectrum of the sun, and it cannot be simply equated with a high-grade thermopile radiometer.

PAR vs. PPFD

PAR focuses on approximately 400–700 nm photosynthetically active bands. More commonly used in agriculture, PPFD represents the flux density of photosynthetic photons, usually in μm ol/(m ² · s).W/m² represents energy flux, which cannot be converted directly and fixedly without spectral assumptions.

0.3–3 What does μm mean?

0.3–3 μm equals 300–3000 nm, covering the solar shortwave range from near ultraviolet to near-infrared/shortwave infrared. Unify μm and nm units before reading the product spectral range.

NiuBoL solar radiation product selection

NiuBoL solar radiation products include thermopile total radiometers, silicon photoelectric radiation sensors, and direct solar radiometers for direct radiation measurements. The total radiation meter of the thermopile covers a wide solar short-wave range, suitable for meteorology and photovoltaics; the PAR/ PPFD sensor should be selected for agricultural photosynthesis research.

Product reference: NiuBoL Solar Radiation Sensor; NiuBoL Pyranometer.

FAQ

Q1: Can illumination Lux replace solar radiation W/m²?

A1: No. Lux is weighted by the visual response of the human eye and W/m² is the energy flux.

Q2: Is the PAR sensor a total solar radiation meter?

A2: No. PAR only focuses on the effective band and photon flux of plant photosynthesis.

Q3: Which kind of radiation should the photovoltaic power station see more?

A3: We usually pay attention to the irradiance of GHI, POA/GTI, etc. Fine items will also measure DNI/Dhi, and combine with the component temperature.