Prior to the official product launch, LI-COR provided the National Renewable Energy Laboratory (NREL) with a set of LI-200R Pyranometers for their long-term solar radiation measurement project. The LI-200R is based on the proven LI-200 Pyranometer, but with a more robust cable and an improved seal against water vapor. The sensor is also detachable from the base/cable, simplifying installation and removal. Click here for a detailed comparison between the old and new sensor designs.
NREL is a US government research facility that focuses on energy R&D and has among the highest standards for solar radiation measurement and instrument calibration accuracy in the world. They have a facility called the Solar Radiation Research Laboratory (SRRL) which facilitates a program called the Baseline Measurement System (BMS) for radiation sensors.
As of April, 2015 the LI-200R Pyranometer has been deployed alongside other sensors at the BMS site. It wasn’t until last August that the sensor was labeled as the “LI-200R”, with data freely accessible and publicly viewable from the NREL SRRL website: http://www.nrel.gov/midc/srrl_bms/.
You can identify, access, view, and download datasets from a variety of sensors, and even plot data using the web interface. Below is an example of a daily irradiance plot made using the NREL data viewing tool.
The LI-200R has provided excellent irradiance measurements when compared to the LI-200 (also at the NREL BMS site) and other more expensive designs, including the Eppley PSP.
Find out more about the NREL trials at http://www.nrel.gov/solar_radiation/facilities.html.
For more information about using the LI-200R Pyranometer for solar energy applications, visit www.licor.com/200R.