[werk_ag]

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The supply voltage is specified as 3.0 +/- 10% so ideally you should adhere to that (but a nominal 3.3 v is probably"safe").  The output signal voltage is also up to 3 volts (1.67 mV/W/m2), ...

Thank you Alan for the info.

Thanks. I think I'll stick to supported instruments.

Do you already have the Davis pyranometer? If yes, it could worth trying.
Otherwise you can opt for the Apogee SP-110: Self-Powered Pyranometer which is supported, or even try to build our solar cell based homemade pyranometer.