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Appendix d. wind direction measurement theory, Appendix d – Campbell Scientific 034B-L Met One Windset User Manual

Page 31

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Appendix D. Wind Direction

Measurement Theory

It is not necessary to understand the concepts in this section for the general

operation of the 034B, Wind Set with a Campbell Scientific datalogger.

A 034B purchased from Campbell Scientific has a 9.53 kΩ fixed resistor and a

variable resistor on the excitation line. The variable resistor is adjusted by the

manufacturer so its resistance plus the 9.53 kΩ resistor equals the resistance of

the potentiometer (R

f

= R

s

+ R

t

).

FIGURE D-1. 034B potentiometer in a half bridge circuit

The vanes are calibrated due south and then the potentiometer is adjusted until

each half of the potentiometer has equal resistance.

D-1