Campbell Scientific UT20 and UT30 Tower-based Weather Stations - Manual (Page 64)

UT20 and UT30 Tower-based Weather Stations
1. Establish a reference point on the horizon for True North.
2. Sighting down the instrument center line, aim the nose cone, or counterweight
at True North. Display the input location for wind direction using the *6
Mode of the datalogger, or, the Monitor Mode of LoggerNet with an on-line
PC.
3. Loosen the band clamps or set screws that secure the base of the sensor to the
mast or crossarm. While holding the vane position, slowly rotate the sensor
base until the datalogger indicates 0 degrees. Tighten the band clamps or set
screws loosened previously.
4. Engage the orientation ring indexing pin in the notch at the instrument base
(05103, 05106, and 05305 sensors only), and tighten the band clamp on the
orientation ring.
* Other methods employ observations using the North Star or the sun, and
are discussed in the Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume IV - Meteorological Measurements 4 .
Subtract declination from 360° Add declination to 0°
FIGURE 8-33. Magnetic declination for the contiguous United States
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