7
INSTALLATION
VP-4
7
Installation
Installation in a Radiation Shield
Relative humidity is measured at the temperature of the humidity
sensor. For this to be an accurate representation of the atmospheric
humidity, it is critical that the humidity sensor be at air temperature.
For most outdoor and greenhouse measurement scenarios, house the
VP-4 in a radiation shield with adequate air flow to allow the sensor
to come into equilibrium with air temperature.
In general, tem-
perature and humidity measurements become more accurate as wind
speed increases. A radiation shield is not critical for non-greenhouse,
indoor monitoring applications where radiation loading is small.
Decagons radiation shield comes with a mounting bracket and seven
discs that prevent direct sunlight from coming into coming contact
with the sensor. This isolation from solar radiation prevents false
readings of elevated temperatures, allowing for accurate measure-
ment of ambient air temperature. To install the sensor in the radia-
tion shield follow the directions 1 through 4.
1. Gently pry the white cap from the bottom center hole of the
radiation shield.
2. Slide the white cap onto the cable of the sensor.
3. Insert the sensor into the bottom of the shield and snap the
cap back into place.
4. The unit can then be mounted on the desired surface for your
study.
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