Then there second type which is based on a filtered microphone, and is typically, fastened to a wall close to the glass. These react to the frequency of breaking glass. This type of detector manages to filter out all the other sounds that could cause a false alarm. Widely available and reliable. Detection area is limited in both types of detectors, to within a maximum effective distance.
Seismic detectors are sensitive to a frequency range that covers vibration.
These are used on safe doors, walls or roofs. A bank may have seismic detectors on the six surfaces of the vault in addition to light sensitive detectors inside and around the enclosing walls, in addition to movement detectors in the area inside and around the walls of the vault. Water detectors are, as the name implies, sensitive to damp and water. Water coming in contact with the detector will cause changes in the resistance of the detector, which in turn will be interpreted by the sensor as water, or at least liquid. Handy in winter for warning of burst pipes and in places where there is a danger of water spillage, such as the rooms where there are washing machines and dish washers.