Glass break sensors often come as standard with car alarms in New Zealand.
As the name suggests, they are designed to detect if a window has been smashed.
Most are little more than a glorified microphone that detects high pitch sound and in turn, triggers the alarm.
Normally they are installed in the front area of a vehicle, either below the dashboard or above it.
Why Glass Break Sensors are not very effective
One of the weak points of a glass break sensor is that they are not very effective in large vehicles. For example, a sensor fitted in the front of a van is unlikely to detect sound in the back, let alone protect against a sliding window being removed. They are also not recommended for vehicles where window tint film is fitted.
Pillar-less windows and tint film both stop glass break sensors being effective
Dynatron/Cyclops Glass Break Sensor
Window tint film muffles the sound of glass breaking. Glass break sensors can also cause a false alarm if the sensitivity is set to high. The materials inside a car can cause a creaking sound as they expand and contract with a change of temperature which can be enough to trigger an overly sensitive sensor.
Ultrasonic sensors are a far more effective and reliable way of protecting the internal space in a vehicle and would be my choice over a glass break sensor every time. Thatcham approved alarms (CAT 1 and CAT 2-1) require a movement sensor, such as ultrasonics or a microwave sensor, so glass break sensors are not approved under these standards.
