Weather Display > WD Feature Suggestions

WMR200A/THGR80 solar transform to approximate solar flux

(1/1)

Brian A:
Guys,

Look at curve 5.   This is the % solar display using a WMR-200A with THG80 modified by replacing the thermistor with CdS photocell and some "transformed" curves

The original response is really squashed near 100%.  A 92% solar reading actually represents something like 60% sky brightness. 

After slogging through the math of thermistor response, CdS photocell response and making some assumptions, a transformation form was found that produces a better display.  Better in the sense that the amount of cloudiness is resolved better and the results more closely approximate the solar flux curve from WD.

The curve shows the WD solar flux, the unadulterated % solar and two transformed plots.
The transformation equation is given on the plot.  "a" is what I call the exaggeration factor.   An "a" value of 1.8 fell out of the math given the assumptions made.  An "a" value of 3 is closer to the solar flux curve .

The curves are choppier than it would be in WD since the customtextout.txt file only gives integer values for % solar. 

I wonder if others would like to try this transformation and see how it works for them.   You have to of course do it on the outside by exporting the solar % values, transforming them and then plotting.  Try different values of "a".

Navigation

[0] Message Index