The LI-200R is designed for field measurement of global solar radiation in agricultural, meteorological, and solar energy studies. In clear unobstructed daylight conditions, the LI-200R compares favorably with first class thermopile type pyranometers but is priced at a fraction of the cost.

The LI-200R features a silicon photovoltaic detector mounted in a fully cosine-corrected miniature head. Current output, which is directly proportional to solar radiation, is calibrated against an Eppley Precision Spectral Pyranometer (PSP) under natural daylight conditions in units of watts per square meter (w/m-2). Under most conditions of natural daylight, the error is < 5%.

Ideal for agricultural, meteorological, solar energy, and environmental research, the LI-200R is available with a variety of cable lengths and is compatible with most data loggers.

  • Weather resistant and durable in long-term outdoor deployments
  • Measures global solar radiation under unobstructed natural daylight conditions
  • Uniform sensitivity up to 82° incident angle
  • Detachable sensor simplifies installation and removal, making it ideal for platforms with complex cabling

Technical Specifications

Absolute Calibration:Calibrated against an Eppley Precision Spectral Pyranometer (PSP) under natural daylight conditions. Calibration uncertainty under these conditions is estimated as ± 3% typical, within ± 60° angle of incidence.
Sensitivity:Typically 75 μA per 1,000 W m-2
Linearity: Maximum deviation of 1% up to 3,000 W m-2
Response Time:Less than 1μs (2 m cable terminated into a 147 Ohm load)
Temperature Dependence:± 0.15% per °C maximum
Cosine Correction:Cosine corrected up to 82° angle of incidence
Azimuth: ± 1% error over 360° at 45° elevation
Tilt:No error induced from orientation
Operating Temperature Range:−40 °C to 65 °C
Relative Humidity Range:0% to 95% RH, Non-Condensing
Detector:High stability silicon photovoltaic detector (blue enhanced)
Sensor Housing:Weatherproof anodized aluminum body with acrylic diffuser and stainless steel hardware; O-ring seal on the sensor base
Size:2.36 cm diameter × 3.63 cm (0.93” × 1.43”)
Weight:24 g head; 60 g base and cable (2 m) with screws
Cable Length:2 m, 5 m, 15 m, 50 m (6.5’, 16.4’, 49.2’, 164’)


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