The direct entrance optic is a special designed telescope which allows the study of the direct irradiance of the solar radiation. It has a weatherproof housing and is designed for use with a quartz fibre. The optic has a field of view of about 1.5°. The outer dimensions allow easy mounting on common solar trackers.
The calibration can be done by applying the KS-J1011 portable spectral irradiance source and the appropriate adapters (KS-J1011-ADAPT-GLO + KS-J1011-ADAPT-DIR).

The drying agent J1020-DRYING-K10 is the standard drying cartridge for the direct entrance optic J1004. Operational for global entrance optics UV-J1002, UV-J1002-REG, and other atmospheric radiation instruments like YES pyranometers and Solar Light biometers.

The drying agent has a filling of about 12 g silica gel (orange). This amount of drying agent allows a longer servicing free period. Operational for global entrance optics UV-J1002, UV-J1002-REG, direct entrance optic J1004 and other atmospheric radiation instruments like Solar Light biometers.