The SPS beam ins-rumentation and closed orbit correction

For the running-in and the operation of a large accelerator like the SPS, the beam instrumentation plays a prominent part. Though limiting the beam detectors to where they are strictly necessary, their number is still considerable, leading to a large amount of data to be treated simultaneously. To do this efficiently, hardware and software are equally important. The type of detectors is determined by their function, intensity, position, profile, loss, etc... whereas the type of associated electronics and acquisition systems is restricted to a minimum for simplicity, production cost, easy maintenance and fast data treatment. The performance of the main types of detectors is summarised giving some particularities of their hardware and software with some emphasis on the closed orbit measurement and correction system. (6 refs).