A tilt sensor, or tilt switch, is a device used for measuring the tilt of an object in multiple axes with reference to an absolute level plane. They are small and compact instruments which make them a viable option for many applications where orientation or inclination detection is a key factor, such as warning systems on construction or agricultural vehicles.
Tilt sensors work by detecting changes in angle from a pre-set “zero” state. They are set with a maximum and minimum threshold in which the application will work or be safe to operate based on the specific application’s needs. If the tilt or inclination exceeds these threshold values in either direction, a relay will be engaged and the switch closed, thus sending an operation to an external device such as an alarm or warning light to indicate unsafe or non-working conditions.
Key applications include:
- Bank angle warning system for ride-on lawn mowers
- Safety cut-out for cranes with hydraulic levelling
- Tilt warning system for platform and hoist levelling
- Rollover warning system for agricultural vehicles
- Safety cut-out for aerial work platforms
Other Types of Tilt Switches
You may see many tilt switches today labelled as “non-mercury”. This is because tilt switches in the past, and some today, operate by opening and closing the switch using a small piece of mercury to close the circuit. Depending on the angle and direction of tilt, the bead of mercury comes into contact with an electrode on one end which would determine when it is at an angle exceeding the threshold.
Tilt ball switches are now more commonly used as an alternative to mercury ones, using a metallic ball to act as the mechanism which either opens or closes the circuit. Again, this is dependent on the angle and direction of tilt and therefore location of the ball. Ball switches are now much more common that mercury ones due to their safety and non-toxicity, but they have significant drawbacks such as a lack of noise filtering that means they cannot be used in high-vibration applications.
MEMS sensor switches have many benefits over these other types of tilt sensors. They are far more precise and reliable, as well as having an adjustable trip angle threshold. They also have the functionality to filter noise out for more heavy-duty applications.