Measuring and control system
Non-contact and wear-free measuring technology is used wherever lengths, angles, rotational speeds or inclinations have to be measured reliably. In addition to data precision, reliable repeatability and robustness of the assembly and operation are important as well.
TÜV SÜD provided certification service for a measuring and control system to attest that it fulfils the elevator requirements with regards to car position and switching and control functions. We also ensure that the system is compliant with the regulatory standards such as EN 81-20 and EN 61508 as well as the EU Lifts Directives.
The measuring and control system is based on the magnetic measuring principle. It consists of three components, a sensor, a magnetic tape with absolute coding and a tape presence switch for presence detection. The space-saving measuring system is able to perform even in the presence of smoke, e,g, in case of fire or contamination.
The SIL3 PESSRAL system detects current and absolute car position by scanning the coded magnetic tape. The absolute car position is then processed internally in the certified system. The speed and acceleration are calculated using the data and converted into corresponding switching functions via safety relays. The safety relays are switched within the door zones of the stored floor positions to enable evacuation of the lift car in case of emergency.