Owner's manual

Model 020C Wind Direction Sensor

7. Installation

Before installation:

• Check to see that the vane assembly rotates freely.

• Ensure that the vane assembly is balanced and the counterweight is

tight by holding the sensor horizontal to verify balance.

7.1 Select Output Range

The output voltage range of the 020C is pre-set at 0 to 5 Vdc at a jumper under

the outer cover of the main body of the probe. The cover is held in place by

friction fit against two O-rings. To change the range to 0 to 2.5 Vdc, carefully

slide the outer cover down to expose the circuit board. A set of three jumper

pins is mounted at the top of the board. Set the jumper block over pins E1 and

2.5. Replace the cover by completely sliding it back over the top O-ring.

7.2 Siting

Locate wind sensors away from obstructions such as trees and buildings. A

general rule is that a horizontal distance of at least ten times the height of the

obstruction should be between the wind set and the obstruction. If mounting

the sensor on the roof of a building is necessary, the height of the sensor above

the roof should be at least 1.5 times the height of the building. See Section 9,

References, for resources that discuss siting wind sensors.

7.3 Assembly and Mounting

Tools required:

• 1/2” open-end wrench (for CM220)

• 5/64” and 1/16” Allen wrenches

• compass and declination angle for the site (see Appendix A, Wind

Direction Sensor Orientation)

• small screwdriver provided with datalogger

• UV-resistant cable ties

• small pair of diagonal-cutting pliers

• 6- to 10-inch torpedo or spirit level

Mount the CM200-series crossarm to the tripod or tower. Orient the crossarm

North to South with PN 1049 or CM220 at the North end of the crossarm.

Remove the alignment screw at the base of the 020C (previous Figure 4-1).

Insert the 020C into the aluminum bushing provided with the sensor. Align the

hole in the bushing with that in the 020C base and replace the screw. Insert the

020C with bushing into the Nurail

or the CM220 u-bolt (Figure 7-2). Align

the sensor such that alignment notches, alignment screw, and counterweight

point true South. Tighten the set screws (PN 1049) or U-bolts (CM220).

Appendix A, Wind Direction Sensor Orientation, contains detailed information

on determining true North using a compass and the magnetic declination for

the site.