Model PMA2132 Digital Quantum Light (PAR) Sensor

Solar Light’s Model PMA2132 Digital Quantum Light (PAR) Sensor measures the photon flux in wavelength range from 400 to 700 nm. There is a proportional relationship between the number of photons absorbed in 400 to 700 nm band and the rate of photosynthesis in plants. The energy of a photon is proportional to its frequency, and therefore inversely proportional to wavelength. In order to produce a signal proportional to the photon flux (number of photons per unit of area per second) the sensor’s spectral power response (Amps/[W/cm2]) must be inversely proportional to the photon’s frequency and thus proportional to wavelength. Traditionally the quantum flux is measured in micro-moles (micro-Einsteins)/s/m2. The conversion factor is:

The angular response of the PMA2132 sensor is cosine corrected, and suitable for measurements of diffuse radiation or radiation from extended sources. Several packages are available for different types of environments, including standard, weatherproof, and waterproof chassis.