![ST-5 Sun Tracker with Shadow Disc Assembly](/sites/default/files/2024-03/ST-5%20Sun%20Tracker%20with%20shadow%20disc%20-%20border%20-%20800px.png)
The ST-5 Sun Tracker's shadow disc assembly can be used in conjunction with the SolarSIM-G to enable highly accurate measurements of diffuse horizontal spectral irradiance and DHI. The shadow disc assembly can also be used with third-party pyranometers to enable highly accurate measurements of DHI and meets the requirements for Class A DHI measurement for solar power plant applications.