PAR sensors & meters

QSO-S photosynthetically active radiation


  • Measure photosynthetically active radiation (PAR) or photosynthetic photon flux (PPF)
  • Low cost, high accuracy sensor that is ideal for researchers and growers
  • Measure the plant growth environment
  • Easy-to-use, calibrated sensor that is ready to measure
  • Connect to our range of data loggers or handheld meters

The model QSO-S PAR Photon Flux sensor measures the Photosynthetic Photon Flux (PPF), also known as PAR (Photosynthetically Active Radiation) in μmol m-2 s-1 from a field of view of 180 degrees.

The QSO-S is ideal for scientific researchers and commercial growers because it characterises exactly the light environment that is experienced, or sensed, by plants. The information measured by the QSO-S can be used to determine plant growth, yield and to parameterize models.


handheld or continuous measurement options

Edaphic Scientific can supply the PAR sensor with either a handheld, portable meter or we can connect the sensor to a data logger for continuous measurements.

For continuous measurement, the QSO-S is supported by the ZL6 Data Logger or Wireless Data Logger. The PAR sensor connects directly into the ZL6 and is pre-programmed and ready to measure.


weather station options

Weather StationFor optimal measurements, the QSO-S PAR sensor can be connected to our range of weather stations.

The QSO-S sensor provides valuable measurements on the light environment. However, this information can be incomplete because it does not include other important variables for plant growth including rainfall, temperature, relative humidity, vapour pressure deficit (VPD) and wind speed and direction. By connecting the QSO-S to a weather station system, complete knowledge of the plant growth environment can be obtained.



feature specification
Spectral Range 400 to 700nm
Accuracy ± 5%
Resolution 2 μmol m-2 s-1
Field of View Hemispherical, 180°
Measurement Range Linear Range: 0-1000 mV (0-5000 μmol m-2s-1) | Full Sunlight: 400 mV (2000 μmol m-2s-1)
Calibration Sensors are calibrated for outside use.
Conversions 5.0 µmol m-2 s-1 per mV
Operating Temperature -40 to +60°C
Power Supply None, self powered
Cable Length Standard: 5m | Extendable to custom lengths
Cable Connector Types 3.5 mm "stereo" plug | 3 core bare wire
Sensor Dimensions 2.4 cm x 2.75 cm
Data Logger Compatibility ZL6 | ES-SYS range
Warranty One year, parts and labor

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