The product

Our QPAR is a PAR measurement station for professionals, researchers, and amateurs. Beyond the measurement, it allows you to understand and optimize the effect of PAR on your plants and their production.


For which applications?

Which LED systems to choose, when to change your light bulb, etc.? QPAR helps you decide. It allows you to optimize and reason your growing environment. QPAR provides a way of comparing lighting systems and monitoring their state over time. Eight values can be stored in the device (saved even without a battery) and one of them can be designated as the “reference”. Evaluating the evolution of the reference value over time allows monitoring the aging of the system.


If you can estimate whether the PAR is limiting, ideal, or too intense for your plants, you can optimize your production! Therefore, we have also added a photosynthesis model that transforms the measured PAR into potential photosynthesis. It is developed by our scientists from research papers studying different plant species (Zea mays, Arabidopsis thaliana, Cannabis sativa/indica, Solanum lycopersicum, etc).


What is PAR?

PAR (Photosynthetically Active Radiation) is a concept that comes from horticulture: to measure the flow of photons whose wavelength (400-700nm) activates photosynthesis (PPFD = Photosynthetic Photon Flux Density, µmol.m-2.s-1). Unlike Luxmeters which perceive light like the human eye and are intended for photography, PAR sensors perceive light like the leaves of your plants. PAR sensors are often very expensive and are intended for scientists and the horticultural industry. We are therefore proud to offer our PAR measuring station at an affordable price, thanks to an innovative and automated calibration method. Our sensors are individually calibrated and tested under different lamps (e.g. HPS and bi-spectrum neon). This allows us to offer a reliable and accurate sensor.



Our PAR measurement station includes all the features needed for horticulture:

  • Spectral response: 400 to 700nm
  • Accuracy: 1µmol.m-2.s-1
  • Measurement resolution: ~ 0.35µmol.m-2.s-1
  • Typical error <2% (maximum 5%)
  • Recording of measurements (8 slots + 1 reference) for comparisons over time
  • Photosynthesis model that transforms PAR into potential photosynthesis
  • Customizable coefficient (to change sensor or test another sensor on the market)
  • Automatic shutdown after 10min of inactivity
  • Low battery indicator
  • ARDUINO compatible for customer reprogramming (ATMEGA328P)


To go further

You can download the manual of your QPAR. You will find all the information you need to take control of your QPAR and understand what photosynthesis depends on. We explain how light, temperature, CO2 and your practices can influence, for good or bad, the growth of your plants.

QPAR - Photosynthesis Active Radiation Quantifier