An inclinometer (also known as a tilt indicator or level indicator) are mechanical or electronic tools that measure the inclination of a surface relative to the earth's surface (gravity). Levels vary from simple mechanical devices to complex electronic sensors that digitally readout angular level values (as does the RAD2 Remote Angle Display). Mechanical levels use a bubble or ball in a vial (typically curved)-filled with a damping fluid, or a pendulum to indicate level.
Electronic or digital inclinometers put out an electronic signal proportional to the angle of lift, relative to level (or horizon). Internally, the inclinometer consists of a tilt sensor and signal-conditioning electronics. These normally reside in one enclosure with either a cable or connector.
Tilt sensors and inclinometers generate an artificial horizon and measure angular tilt with respect to this horizon. They are used in cameras, aircraft flight controls, automobile security systems, and special switches - or any application that requires a tilt or angle measurement. Important specifications to consider when searching for tilt sensors and inclinometers are the tilt angle range and number of axes. The tilt angle range is the range of desired linear output measured in degrees. The number of axes the inclinometer and tilt sensor measure on is another important specification.
Common sensor technologies for tilt sensors and inclinometers are accelerometer, capacitive, electrolytic, gas bubble in liquid, mercury, and pendulum.
Rieker's RAD2 system uses liquid capacitive inclinometer sensors. Since this type of technology has no moving parts (nothing to break) and has a natural built-in shock and vibration resistance, the sensors are extremely durable for rough environments.