[JT118]

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Fell free to create the new thread .

Hi
Would it be possible to use a wind sensor such as the WSD1 from Environmental Measurements Ltd
This uses a continuously rotating potentiometer which could be connected as a voltage divider circuit.
http://www.emltd.net/products/wind/wind-...on-sensors
Thanks

I spotted this difference, and although I have not quantified it, I was surprised because it seemed very significant. This led me to suspect that the wind factor used by me for the FO anemometer could be wrong (I used the value specified in the Argent Systems datasheet for the FO anemometers). Then I remembered a discussion that I read some time ago, in the Cumulus forum, which according to some calculations the real wind factor for FO anemometers should be lower than the one I used, but only 5%, which does not justify this difference of nearly 20%.

I have also checked whether the cause of this difference is not in the readings of the Inspeed Instruments, but I can't find any fault. Both are using the same routines to read the pulses. (obviously the formula to calculate the wind speed and gust, uses a variable derived from the Wind Factor and pulses per revolution, for each one).

I suppose the main problem with the FO instruments is that they are manufactured to a price rather than to a quality. I suspect that if we set up a scientific experiment with 7 or more replicates, we would find considerable variability between the 7 FO instruments. It would be interesting to alter the software maths by 18% and see what the results yield.