Decagon Devices VP-3 Operating Manual page 13

Temperature
The VP-3 has a band gap temperature sensor integrated into the
sensor electronics. The temperature sensor is co-located with the
RH sensor and will accurately measure the sensor temperature.
If the VP-3 is adequately radiation shielded and aspirated, the
sensor temperature will be very close to air temperature.
Vapor Pressure
Vapor pressure is calculated from the primary measurements of
sensor RH and sensor temperature.
pressure (e ) is calculated from the sensor temperature using the
s
Magnus-Tetens equation for calculating saturation vapor pressure
over liquid water formulated by Murray (1967)
e = a exp
s
9
VP-3 User's Manual
The saturation vapor
 
1 1
b T
 
-------------- -
 
T + c
a
2. Measurements