On-line monitoring of beam quality for high brightness beams is only possible using non-invasive instruments. For matching measurements, very few such instruments are available. Therefore, a new type of quadrupole pick-up, sensitive to the beam width, has been developed for the CERN PS. A measurement system consisting of two such pick-ups has been installed in the accelerator. Using the information from these pick-ups, it is possible to determine not only the injection matching in the two planes, but also the emittances. Both measurements use the periodicity of the circular machine to eliminate a number of systematic error sources, while the statistical error is reduced by using data from several turns. The analysis can be done on each bunch separately. This is required because of the PS filling scheme, where each injected bunch comes from a different Booster ring, and therefore can have different properties. After an overview of the measurement system, some of the first measurement results are presented along with a discussion on the measurement error.
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