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monitoring sun radiation

I am trying to derive the kWh from the sun's radiation using a Kipp&Zonen CMP11.


I have sampled readings from the CMP 11 (which is in Watt per square meter) using an agillent mux.  Now I have to integrate it over the accumulating time to get the Watt-hour.  Which function can I use?  Can I use the Time-Domain Integration vi SUM[X(dt)]?

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Message 1 of 7

You can use Numeric Integration VI.  It locates at Mathematics >> Integration & Differentiation palette.

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Message 2 of 7

Thank you,


I forgot to mention that I am doing real-time sampling and accumulating the kWh continuously.

I tried the Integral (Sum[Xdt]), also in the math palette, and seemed rather straight forward to implement. I have not seen anyone use this vi for this purpose, perhaps its a new feature in Labview?


I am not certain of how to use the Numeric Integr VI for the same purpose.  What do I use for dt (interval size)?  The sampling period?

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Message 3 of 7

Which VI do you use? The Integral x(t) VI?


Yes, dt is sampling period.

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Message 4 of 7

 This is what I used.  Its in the math > Integr & Diff > Time-Domain Math


Integral (Sum[Xdt]).jpg

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Message 5 of 7

I see. 


You said you are doing real-time sampling and accumulating the kWh continuously.


Do you mean point-by-point?  That is, every time you get a sample data input, you want to calculate the integral?


If so, you can use Integral x(t), which is in Signal Processing >> Point By Point >> Integral & Differential PtbyPt palette.



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Message 6 of 7

How were you able to take measurements with your CMP11? I have a CMP3 and am having difficulty reading the microvoltage created with my compactdaq. would you mind sharing your block diagram?

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Message 7 of 7