Information about Linear Position Sensors, Fiber Optic

Fiber optic linear position sensors use fiber optic technology to sense position and displacement. They use an adjacent pair of fiber optic elements, flexible strands of glass that transmit light along their length by maintaining the near-total internal reflection of light accepted at the input. One fiber optic element carries light from a remote source to the object or target whose displacement is to be measured. The other fiber optic element receives the light reflected from the object and carries it to a remote photosensitive detector. Output types include analog current levels, analog voltages, modulated analog outputs, and digital signals. Analog current levels such as 4 – 20 mA are suitable for sending signals over long distances. Analog voltages are simple, usually linear functions. Modulated analog outputs such as sine waves, pulse waves, amplitude modulation (AM), and frequency modulation (FM) signals are encoded, but still analog in nature. Several types of digital outputs are available. RS232, RS422, and RS485 are common serial, digital protocols. Popular parallel protocols include the general-purpose interface bus (GPIB), a standard which is also known as IEEE 488. Other digital outputs for inductive linear position sensors and switches include transistor-transistor logic (TTL) signals.

Cable Extension Linear Position Sensors

Cable extension linear position sensors are used to measure the movement and displacement of objects. A cable or wire is attached to an object, and as the object moves, the transducer produces an electrical signal proportional to the wire's linear extension.

Linear Position Sensors and Switches, Ultrasonic

Linear position sensors and switches, ultrasonic, are used for position and displacement sensing, using ultrasonic technology.

Linear Position Sensors, Capacitive

Capacitive linear position sensors are devices that sense position / displacement using capacitance technology.

Linear Position Sensors, Eddy Current

Eddy current linear position sensors detect the distance from a target by using magnetic fields generated by a reference and sensing coils.

Linear Position Sensors, LVDT

Linear variable differential transformer (LVDT) linear position sensors have a series of inductors in a hollow cylindrical shaft and a solid cylindrical core. These devices produce an electrical output proportional to the position of the core

Photoelectric Sensors

Photoelectric sensors use emitters and receivers to detect the presence, absence, or distance of target objects.

Position Sensors, Optical Triangulation

Optical triangulation position sensors use reflected waves to pinpoint position and displacement.