Pyranometer—LI-COR LI-200R

The LI-200R Pyranometer measures hemispherical solar radiation and provides analog data to the Sutron 9210B datalogger. Here we provide basic installation and operation instructions for using the LI-200R-SMV and LI-200SL in a LI-COR eddy covariance system with a biomet system running Biomet_100 and Biomet_102 programs.

LI-200R Specifications:
Spectral Response: 400 to 1100 nm
Energy Range: 0 to 1000 W/m2
Absolute Calibration: ±5%
Output Signal: 0 to 10 mV
Linearity: Max. deviation of 1% up to 3,000 W m-2
Cosine Correction: up to 80° angle of incidence
Azimuth Error: <1% over 360° at a 45° elevation angle

Installing the LI-200R

  1. Siting the Pyranometer.
    • Position the LI-200R so it will never be under a shadow, either from the surrounding landscape elements or from the tower itself.
    • Mount the sensor on the tower to minimize reflected radiation that is visible to the sensor.
  2. Mount the Pyranometer.
    • Mount the LI-200R in the mounting and leveling fixture (2003S).
    • Attach the 2003S to the 7900-350 radiation sensor bracket and level the 2003S.
    • Secure the cable to the tower using zip-ties.
  3. Wire the Pyranometer to the Datalogger.
  4. LI-200R Pyranometer is supported by datalogger programs Biomet_100 and Biomet_102. For custom datalogger programs, use the SolRad block and configure it as described in Pyranometer (LI-200R or LI-200SL).Route cables through an opening in the bottom of the enclosure.Note: Route the sensor cable(s) through an opening in the enclosure prior to installing the leads in the terminal strip.

Description Color AIO2 Terminal
Negative Black 4 (CH3)
Positive Red 6 (AGND)

Since the datalogger reads ± signals, connect the positive (red) lead to the common (low) terminal, and connect the negative (black) lead to signal (high) input.

Important: The millivolt adapter is not weatherproof. Keep it inside the enclosure for protection from the elements.

Retrieve Data

If the system is configured to log biomet data in .ghg files for processing in EddyPro software or the SmartFlux System, data are stored on the removable USB storage device. Refer to the Biomet Instruction Manual for details.


  • Keep the surface and vertical edge of the acrylic diffuser clean.
  • As needed, clean the diffuser sensor with water, mild detergent, or vinegar dilute using a soft, lint-free cloth.
  • DO NOT use alcohol, organic solvents, strong detergents, abrasive solvents, or abrasive cloth on the diffuser.
  • Return the sensor to LI-COR for factory recalibration every two years. Contact technical support for more information.