LI-190R measurement of photosynthetically active radiation (PAR), unit µ mol s^-1m^-2Accurately measure PAR in various environments, including outdoor, greenhouse, under canopy, and inside growth chambers. Suitable for various broad-spectrum light sources, including natural sunlight, artificial light sources, and hybrid light sources. Measure the wavelength range of 400-700nm for the vast majority of plants
The frequency band utilized by photosynthesis.

working principle
LI-190R adopts high-quality silicon photodiodes, combined with glass optical filters, to achieve uniform response between 400-700nm. The latest designed optical filter accurately filters the detection band, and the band response rate is as close to the ideal value as possible (see the figure below), and the new filter is not affected by environmental temperature and humidity. The filter effectively blocks light above 700nm, which is crucial for studying illumination under vegetation, as infrared radiation under vegetation is relatively high compared to visible radiation.
The sensor exhibits excellent cosine response, ensuring accurate measurements when scattered light is strong and the solar elevation angle is low. LI-190R can maintain high resolution even under low light intensity, making it more advantageous in determining plant light compensation point measurements.

Application field

Greenhouse and growth chamber lighting monitoring
Research on Agricultural Yield
Micro meteorological research, etc

Main advantages

The measurement of PAR signals at all wavelengths is uniform and accurate, and does not require recalibration whether outdoors, under vegetation, or with artificial light sources
The latest optical filters ensure unprecedented ideal wavelength response
Tolerate various weather conditions such as high temperature and humidity, and adapt to long-term outdoor placement
Cosine correction ensures accurate measurement of sensors even when there is no direct light
Detachable sensor head, easy to install and disassemble, convenient for maintenance and calibration

Technical Specifications
Absolute calibration：±5%
sensitivityTypical 5-10 µ A/1000 µ mol s^-1m^-2
linearityThe maximum deviation is 1% (10000 µ mol s)^-1m^-2Within)
response time：<1µs
temperature-related：<0.15%/℃
Cosine correction: Incident angle within 82 °
Azimuth errorAt a 45 ° elevation angle, the error within a 360 ° azimuth range is less than ± 1%
Tilt error: Will not cause errors due to fixed orientation

working environment-40~65 ℃, 0~100% RH (non condensing)

detectorHigh stability silicon photovoltaic detector (blue light enhanced)
sensor housingAnodized aluminum waterproof shell with acrylic diffuser and stainless steel screws; Sensor base with O-ring seal
size:2.36 Day. x 3.63 cm H
weightHead: 24g; 2-meter with screw base: 60g
Cable length：2 m, 5 m, 15 m, 50 m

optional

Origin and Manufacturer: United StatesLI-CORcompany