The PD Controller is an electronic pressure controller. It is extremely precise and is equipped with 2 alarm activation systems in case the set values are exceeded. It has an 0-5 V analogical output. It has been developed for controlling pressures and vacuums in CA storage rooms. It can be connected to the ISOSOFT programme through an interface to visualize graphic data. It is very useful for confirming pressure tests and to check causes of difficulties in keeping O2 levels in CA storage rooms. It is equipped with alarm relays and can be used as a security device, to stop the cooling plant (if required) or other devices that can cause a vacuum in the storage rooms, avoiding potential damage.