The CM 121B/C Shadow Ring can be used with Kipp & Zonen pyranometers, pyrgeometers and UV Radiometers to shield the instrument from direct radiation. The combination of a global measurement instrument and CM 121B/C Shadow Ring offers a simple solution to the problem of measuring diffuse radiation from the sky. The shadow from the ring covers the pyranometer dome completely. The ring will not need adjustment for several days. Naturally the ring will also intercept a small part of the diffuse radiation from the sky. Correction is necessary to compensate for this and a table is provided.

When it is desired to use the shadow ring with an instrument fitted with the CVF 3 ventilation unit it is necessary to order the CM121C version. This has an factory fitted adapter to correct for the extra height of the CVF 3.

A measuring instrument is not included, and must be ordered separately.

Main features :

• Suitable for all latitudes and surfaces in the tilted North-South plane
• A correction table for the whole globe is provided
• Compatible with all Kipp & Zonen CM series pyranometers, CG series pyrgeometers and CUV series UV radiometers