Photodiode-based pyranometer housing and pole mount
This sensor was inspired by the design posted by David Brooks at
The sensor uses a photodiode (Advanced Photonics, PDB-C139), a 470 ohm shunt resistor (1/8 W), and 1-mm thick teflon diffuser.
The printed parts were made from ABS filament using an Airwolf3d printer (AW3DXLkit) with a 0.5 mm nozzle and 0.2 mm layer height.
The Teflon diffuser was 1mm-thick sheet with self adhesive backing ( punched out using 3/8" arch punch). Thus, no adhesive is needed to install the diffuser.
Teflon (PTFE) sheet Size 6" x 12", 0.03" (1/32") thick with 3M 300LSE industrial-strength self-adhesive backing (amazon.com)
The bubble level is 14mm in diameter (ebay).
6-32 machine screws are used for mounting the sensor to the lower plate.
A u-bolt with 1-3/8" inner spacing is used for the pipe mount.
1/4 20 x -3/8 x 2-3/4 U Bolt w Nuts 18 8 SS (nutty.com)
When calibrated against commercial pyranometers from Apogee and Li-Cor, the calibration multipiliers were typically between 3.3 and 3.6 W/m2 per mV.
This design does exhibit some cosine error at large zenith angles which causes a slight underestimate of global irradiance - especially in winter at more northern latitudes.
More designs to come ...