LI-COR LI-190R [LI-190R-BL-5] PAR Sensor w/ Microamp Output, 5m Cable and Bare Leads

The LI‑190R uses a high-quality silicon photodiode and glass optical filters to create uniform sensitivity to light between 400 nm to 700 nm, which closely corresponds to light used by most plants. Precision optical filters block light with wavelengths beyond 700 nm, which is critical for measurements under vegetation where the ratio of infrared to visible light may be high.

Excellent cosine response provides accuracy at low solar angles. This, in combination with high resolution at low light levels, makes the LI-190R useful for determining the light compensation point in plants.