- Frequency range: to above 100 kHz
- Shock and vibration resistant and reliable in oily, wet and harsh environments
- Temperature Ranges: Standard and Extended, High temperature & cyrogenic sensors, -450 to 850° F (-270 to 454° C)
- Easy installation and long maintenance-free life;
- Available in all popular standard and metric sizes
- Air Gaps:
Magnet types: Recommended air gap between the VR speed sensor and the target is 0.001" to 0.003", although air gaps up to .25" are possible depending on sensitivity and target's speed and mass
Inductive types: 1” max depending on magnetic field strength - Shell Material: 303 Stainless Steel; other materials available
Download our VR speed sensors spec sheet:
Specialized VR Sensors:
- Intrinsically Safe to Zone 0
- Dual output
- Additonal output for temperature available
- Hermetically-sealed and sanitary for food processing applications
SPECTEC's line of DigiSpec digital VR speed sensors, pulse amplifiers and frequency to voltage converters are available for applications requiring digital or other sensor outputs.
Variable Reluctance Speed Sensors Applications:
SPECTEC variable reluctance sensors are found in high pressure installations, the harsh environments of oil fields around the world, and in moist, corrosive and noisy electrical environments of ships at sea. Applications of passive VR speed pickups are as vehicle speed sensors, wheel speed sensors, counting and position sensing in industrial applications, such as on conveyer belts. VR sensors are used with such targets as: slotted wheels, sprockets, and bolt heads. Other applications for SPECTEC variable reluctance speed sensors are: ATV tachometer sensors; truck, railroad and marine transmissions; in ABS brake systems for wheel slip and traction control; construction equipment transmission and tachometer applications; and in vehicles for engine RPM, speed and automatic transmission sensors.
Principles of VR SPeed Sensor Operation:
The signal output of a VR sensor is caused by the excitation of its inductive coil by a passing target. As a ferrous actuator, such as a wheel's gear or a turbine's blade, moves past the sensor, the break in the actuator's surface (i.e. a gear tooth) excites a voltage in the VR coil, producing an electrical analog wave. The frequency and voltage of the analog signal is proportional to actuator's velocity. Each passing discontinuity in the target causes the VR sensor to generate a pulse. The cyclical pulse train created by a vehicle's rotating gear, a flow meter's turbine blade or a cotter key slot can be read by counters, meters or governing instrumentation.