The collimator-telescope system (SIS-02) is dedicated to measure angular separation of the secondary image from the primary image on windshield in dedicated position.
ECE R43 Section 9.3
The windscreen is mounted between the collimator and telescope. The user enters the highest allowed deviation angle in minutes, and the system measures the distance between the primary and secondary images. The system will prepare the report and hard copy can be taken if required.