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Weather Conditions Measured/Calculated
Energy EnviroMonitor Manual Page 9
Solar Radiation
What we call “current solar radiation” is technically known as Global Solar
Radiation, a measure of the intensity of the sun’s radiation reaching the earth’s
surface. This irradiance includes both the direct component from the sun and
the diffuse component from the rest of the sky. The solar radiation reading
gives a measure of the amount of solar radiation hitting the solar radiation sen-
sor at any given time, expressed in Watts per Square Meter (W/m
2
). The power
of this radiation, when integrated (summed) over a period of time, gives a
measure of the amount of incident solar energy received during that time
period. This solar energy reading is expressed in Langleys.
Note: The Energy EM measures energy received in the spectral band between 400 and 1100 nm.
• Current Solar Radiation Intensity
• “Daily” Incident Solar Energy Sum (AutoClear)
• Average Incident Solar Energy per day during period
Rainfall
The Energy EM provides two separate registers for tracking rainfall totals. One
is referred to as “daily” rainfall and the other is referred to as “total” rainfall. In
truth, these registers can be used to record rainfall over any period of time you
desire. The “daily” register can be cleared daily using the AutoClear function
(see “AutoClear” on page 12) to provide true daily rainfall totals or you may
clear it manually every few days, after a storm, at the end of the month, etc.
The total rainfall amount must be cleared manually and how often you clear
the register determines what period of time its rainfall total reflects. The
Energy EM also calculates the rate of rainfall using the amount of time between
each .01" or .2 mm rainfall increment.
• “Daily” Rainfall (Alarm: High) (AutoClear)
• Current Rate of Rainfall in inches or millimeters per hour
• Total Rainfall
• Maximum Rate of Rainfall with time of occurrence
1 Langley = 41.84 kiloJoules per square meter
= 11.622 Watt-hours per square meter
= 3.687 BTUs per square foot