PNy(p) series, AC/AC group, like other displacement transducers made by Peltron are based on the differential transformer principle – LVDT. The transformer is placed inside a cylindrical case. There is a magnetic core inside the transformer. Displacement of the core results in a change in the transducer’s output signal. This series is equipped with a return spring so the core is not fixed to a moveable object. Pneumatic version has a air-pressure used to push the core out. One transducer of PNy(p) series works with a one channel conditioner like amplifier WG06. It is used mainly to measure flatness of glass windows.