Why opening contacts

Opening contacts are usually used on windows and doors that are easily accessible from the outside (such as entrance doors or windows leading to balconies), giving the alert rapidly should a door or window be opened. When mounted properly, it is still possible to leave a window ajar to allow fresh air to circulate without causing a false alarm, whilst unwanted openings are still being detected. Contacts can also work to generate alerts for various other applications, e.g. alarm contact for heating systems or fridge doors. )