The sensor is a linearized thermister. Insolation , or solar irradience, is measured with a silicon photocell which looks upward through a diffuser. The Langley is a measure of energy per unit area equal to 1 calorie per square centimeter. The values on the web page are corrected for local zenith angle to reduce ambiguity at low horizon angles. Barometric pressure is measured in Millibars, around 700 to 712 mbar is normal for 10,000 ft elevation.
Rainfall is measured in a tipping bucket that automatically counts hundredths of an inch of rain.
Thus our readings over the long term will probably be a bit low. The instruments used are described in more detail in this document. Comments regarding this system or data can be addressed to Mark Waterson at Mees Observatory. This file last updated 24 April, 1997.