Hall Effect Speed Sensors
Hall Effect sensors detect speed by measuring changes in magnetic fields. When a magnetic target wheel rotates past the sensor, it generates electrical pulses that correspond to speed. These sensors are commonly used in automotive applications for wheel speed, crankshaft position, and transmission speed monitoring. They're highly reliable and work well in harsh environments.

Optical Speed Sensors
Optical sensors use light beams to measure speed. They typically consist of an LED light source and a photodetector. As an object passes through the light beam, it creates interruptions that are converted into speed measurements. These sensors are often found in industrial applications, conveyor systems, and precision machinery where non-contact speed measurement is crucial.

Variable Reluctance Speed Sensors
These sensors generate an AC voltage signal when a ferromagnetic object passes by them. The frequency of this signal is proportional to the speed of the moving object. They're particularly robust and commonly used in automotive engines for crankshaft and camshaft position sensing, as well as in industrial machinery for speed monitoring.

Magnetic Pickup Speed Sensors
Similar to variable reluctance sensors, magnetic pickups generate voltage when a ferromagnetic object passes through their magnetic field. They're self-powered (passive) devices that don't require external power, making them ideal for simple speed sensing applications in engines, turbines, and industrial equipment.

Eddy Current Speed Sensors
These sensors work by detecting changes in electromagnetic fields caused by eddy currents in conductive materials. They're particularly useful for non-contact speed measurement in metallic objects and are commonly used in rolling mills, paper mills, and other industrial applications where precise speed control is essential.

Laser Speed Sensors
Laser speed sensors use advanced optical technology to measure speed with high precision. They work by emitting a laser beam and measuring the reflected light from the moving object. These sensors are used in high-precision applications, quality control, and scientific research where extremely accurate speed measurements are required.

Radar Speed Sensors
Radar sensors measure speed using the Doppler effect, where radio waves are reflected off moving objects. They're commonly used in traffic monitoring, sports equipment, and industrial applications where non-contact speed measurement is needed over longer distances or in challenging environmental conditions.

Ultrasonic Speed Sensors
These sensors use sound waves above human hearing range to measure speed. They emit ultrasonic pulses and measure the time taken for echoes to return, calculating speed based on these measurements. They're particularly useful in applications where optical or magnetic sensors might not be suitable, such as in liquid flow measurement or in dusty environments.