Equipment we use
Infra Red Motion Sensors
These usually come as two slightly different types. The first type consists of two parts, one an emitter and one a receiver. An infra red light beam is emitted between the two parts and if this is broken an alarm will sound. This barrier-beam type is useful for locking off areas or perhaps even placing in amongst a group on vigils and passively monitoring the unit to see if the beam is disturbed. The other type is usually a motion detector unit. A single emitter unit that again emits a wide angle infra red light beam which if broken sounds an alarm or sometimes activates a light.