Insolation Data from Arrie Goforth Elementary School, Norfork, Arkansas (92.2688 W, 36.1972 N) These insolation data have been collected by Wade Geery and his students with a "homemade" silicon solar cell-based pyranometer provided by David Brooks. Data are recorded with an Onset Computer Corporation U12-series 12-bit data logger (www.onsetcomp.com), that also records temperature and relative humidity. Samples are taken at one-minute intervals. Discrepancies between measured maximum insolation and the clear-sky model values are due to a combination of modeling and calibration errors, and do not represent "errors" in the student data. The Excel files containing these data are available from David Brooks.

Heavy frost coats the pyranometer in the early morning, February, 2007. A bubble level is mounted on the left end of the case. On the right end, a small disk of Teflon® covers the detector.
Randy and Jami point to the data logger and pyranometer, late March, 2007.
Downloading data from the pyranometer.

February, 2007
March, 2007
April, 2007
Starting in mid-May, a second pyranometer (displayed in blue) has been added.
This instrument was calibrated by David Brooks against an Apogee pyranometer
and the calibration of the original pyranometer was adjusted retroactively to
agree with this second instrument. In this newer instrument, the detector and its
diffuser are mounted at the end of a PVC tube about 2 cm long, rather than the
diffuser being nearly level with the top of the case.
May, 2007
June, 2007
July, 2007