The LI-200 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%.

The spectral response of the LI-200SA does not include the entire solar spectrum (Figure 1), so it must be used in the same lighting conditions as those under which it was calibrated. Therefore, the LI-200SA should only be used to measure unobstructed daylight. It should NOT be used under vegetation, artificial lights, in a greenhouse, or for reflected solar radiation.

• Calibration: Calibrated against an Eppley Precision Spectral Pyranometer (PSP) under natural daylight conditions. Typical error under these conditions is ± 5%.
• Sensitivity: Typically 90 μA per 1000 W m-2.
• Linearity: Maximum deviation of 1% up to 3000 W m-2.
• Stability: < ± 2% change over a 1 year period.
• Response Time: 10 μs.
• Temperature Dependence: 0.15% per °C maximum.
• Cosine Correction: Cosine corrected up to 80° angle of incidence.
• Azimuth: < ± 1% error over 360° at 45° elevation.
• Tilt: No error induced from orientation.
• Operating Temperature: -40 to 65°C.
• Relative Humidity: 0 to 100%.
• Detector: High stability silicon photovoltaic detector (blue enhanced).
• Sensor Housing: Weatherproof anodized aluminum case with acrylic diffuser and stainless steel hardware.
• Size: 2.38 Dia. ´ 2.54 cm H (0.94” ´ 1.0”).
• Weight: 28 g (1 oz).
• Cable Length: 3.0 m (10 ft).