Belfort AWOS, Maintenance Manual

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-17-
BELFORT
INSTRUMENT
Proprietary Information
5.3 T
EMPERATURE
, H
UMIDITY AND
D
EW
P
OINT
- A
NNUAL
M
AINTENANCE
& V
ERIFICATION
P
ROCEDURES
SAFETY PRECAUTIONS
1. Do not perform outdoor Belfort AWOS maintenance tasks during a thunderstorm.
2. Use extreme caution when lowering the tilt-over tower whenever ice or snow has accumulated
on the tower cross-arm or the sensors. The extra weight may cause the tower to fall over
rapidly.
PARTS AND TOOLS REQUIRED
1. Kestrel Model 3000 Wind Instrument or equivalent
2. Belfort AWOS hand held display
The Temperature and Dew Point Verification Test is a confidence test, which verifies that the
Belfort AWOS air temperature and humidity readings compare reasonably with readings taken by
a calibrated Kestrel Model 3000 Wind Instrument.
VERIFICATION INSTRUCTIONS
1. Turn on the HHDU. Stand near the base of the Belfort AWOS tower, facing into the wind.
Observe the Belfort AWOS wind indicator vane to ascertain wind direction. Turn on the
Kestrel Model 3000, select average mode, and hold the Kestrel Model 3000 at eye level,
square to the wind and record the temperature and relative humidity. If the wind speed is
below 2 mph, wave the Kestrel Model 3000 back and forth several times to assure air
temperature is being measured and not case temperature. Press refresh on the HHDU to get
the most recent Belfort AWOS data. The temperature and humidity readings should agree
within 20%.
2. If either temperature or relative humidity does not agree within 20%, the sensor should be
replaced. Follow the Belfort AWOS System Component Failure Instructions in Section
5.10.