In order to locate the pigs in the pipeline or in the pigging stations I.S.T. has developed various special pig sensors. In automated systems the pig is equipped with an integrated magnet. The field of this magnet is sensed by a special magnetic field switch. For wleded stainless steel stations these sensors are fixed to an externally mounted rod with a special clamp. this allows the sensor to detect the pig through the pipe wall. In cast stations other sensors are screwed into a housing. I.S.T. also offers electro mechanic devices for location of pigs without magnet. For high temperature areas special sensors are also available. All pig sensors are available for EX and NON-EX areas. Pigging stations can also be equipped with manual pig locators. With this type of device a tappet is manually pressed into the station, in order to check for the presence of the pig. The tapped is then automatically removed from the pipeline by a spring. I.S.T. also offers a protable pig sensor pen with which the pig can be detected throughout the pipeline. This method is only applicable for stainless steel pipelines.