
LI-190R
Quantum Sensor
The LI-190R measures Photosynthetically Active Radiation (PAR, in µmol of photons m-2 s-1). It provides accurate measurements—in the open, in greenhouses, under plant canopies, or in growth chambers—for most broad-spectrum light sources, including natural sunlight, artificial, or mixed sources.
Plants use light in the wavelength range from about 400 to 700 nm to drive photosynthesis. The efficiency with which plants use light varies somewhat across this range, but McCree1 showed that measuring PAR provided a consistent way to predict plant photosynthetic response regardless of the spectrum of the light source.2
Request a QuoteTechnical Note: Comparison of Quantum Sensors with Different Spectral Sensitivities

Take Instantaneous PAR Measurements with the LI-250Q Greenhouse Package
Quickly assess PAR intensity and make informed light management decisions. Ideal for growth chambers, LED systems, and related applications.

Log PAR Data and Calculate Daily Light Integral with the LI-1500 DLI Package
Expand your light measurement capabilities with data logging, long-term measurements, and automated calculation of daily light integral.