The measurement of proximity, position and displacement of objects is essential in many different applications: valve position, level detection, process control, machine control, security, etc.

Hall effect sensors are used to detect the proximity, presence or absence of a magnetic object using a critical distance. They function via an electrical potential that is developed across an axis transverse to an applied current flow in the presence of a magnetic field applied to the conductor. Hall effect sensors are designed using a variety of body styles.  Selection of a sensor based on body style will vary by application, as there are specific advantages to each style.  Block type sensors are the most common style.  They are designed to be unobtrusive.  Slot type sensors are designed to detect the presence of a vane or tab as it passes through a sensing slot, or "U" channel.  Barrel styles are of a simple, cylindrical body shape, which is often threaded for easy attachment.  Ring, or doughnut, sensors are designed so that an object can pass through the center of the device.  In some cases, Hall effect sensors, proximity, are employed in limit switch fashion.  In these cases, they are similar in appearance to a contact limit switch, but the sensor is separated from the switching mechanism and provides a limit for the travel detection signal.

Proximity Hall effect sensors are employed in a wide range of applications where magnetic fields and electrical currents could disrupt true readings, and disrupt the flow of data.  For this reason, many sensors are designed with specific shielding or protection features.  The most common feature is simple shielding to filter out EMI/RF "noise.” Other proximity sensors are designed to be weld field immune (WFI), where the weld field must be filtered out both at the oscillator level and the output level.  Other varieties of these sensors can be designed with built-in short circuit protection, or completely close housings to receive an intrinsically safe rating.

Sensors, detectors and transducers covers a wide category of devices used to monitor, measure, test, record, analyze and/or display data as generated due to changes in a measured norm. Major sensor and sensor switch categories include acceleration and vibration, acoustic, analytical, density and specific gravity, electrical and electromagnetic, encoders and resolvers, environmental, flow, force, gas, humidity and moisture, level, linear and orientation position, pressure, Hall effect proximity sensors, presence sensors, rotary position, temperature, tension, tilt, torque, velocity, viscosity, and weather sensors.

Position sensors encompasses a wide range of sensors, switches and technologies that are used to determine the placement, speed or movement, direction, and location of a given target. Linear position devices include cable extension, capacitive, eddy current, fiber optic, Hall effect proximity sensors and other proximity sensor types, inductive, magneto resistive, optical triangulation, photoelectric, position displacement, ultrasonic, and variable resistance technology sensors. Other instruments include laser micrometers, linear encoders, linear potentiometers, and LVDTs. Rotary position sensors include rotary encoders and angular position sensors. Orientation position sensors include encoders, inertial gyros, and inclinometers.