Variable Reluctance Speed Sensors
Variable reluctance speed sensors are like coils or solenoids wrapped around a magnet and pole piece. They don’t need external power and have two leads: power and ground. The sensor generates voltage when a gear tooth moves near it. The rotating target’s frequency can then be used to determine the speed of the application. Factors like the diameter of the target wheel and the dimensions of each tooth affect the calculation. So, VR sensors are a simple yet effective way to measure speed in various applications.
A variable reluctance sensor (commonly called a VR sensor or magnetic pick-up) is a transducer that measures changes in magnetic reluctance. When combined with basic electronic circuitry, the sensor detects the change in the presence or proximity of ferrous objects.
With more complex circuitry and the addition of software and specific mechanical hardware, a VR sensor can also provide measurements of linear velocity, angular velocity, position, and torque.
VR sensors, also known as passive or electromagnetic sensors, do not require an external supply.

Features
- No external power supply required
- High reliability. Long life
- Robust 2- wire installation
- No moving parts or contacts
- Operating Temp -40 °C to + 185 °C
- Wide speed rage
- Pole piece from .040″ to 311″
- Spade, conical, round, or blind pole pieces available
- Customized versions available
- Adapts to various configurations
Sizes Available | |
Tubular | .150″ to .500″ inch diameter |
UNF Thread | 1/4-28 to 3/4-16 inch |
Metric Thread | M12X1.25 TO M22X1.5 |
Other VR sensors in this category

MSC 401007-50
Description: VR Speed Sensor
Thread: 3/8-24
Thread Length: 2.70 in
Lead Wire Length: 7.75 in

MSC 401029-20
Description: VR Speed Sensor
Thread : 5/8-18 in UNF-2A
Thread Length: 4.90 in
Lead Wire Length : 5.60 in

MSC 401029-30
Description: VR Speed Sensor
Thread: 5/8-18 in UNF-2A
Thread Length: 5.49 in
Lead Wire Length: 3.59 in

MSC 401072-90
Description: VR Speed Sensor
Thread: M16 x 1.5 |
Thread Length: 3.13 in
Lead Wire Length: 4.25 in

MSC 401092-80
Description: VR Speed Sensor
Thread: 3/4-16 in
Thread Length: 2.57 in
Lead Wire Length: 3.50 in

MSC 401070-70
Description: VR Speed Sensor
Thread: 5/8-18 in UNF-2A
Thread Length: 1.48 in
Lead Wire Length: 2.62 in
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Functions and Applications for MSC’s Variable Reluctance Sensors
SENSOR TYPE |
Active Digital Output |
Variable Reluctance Speed Sensor with Digital Output |
Passive Analog Output |
Variable Reluctance Speed Sensor |
Variable Reluctance Speed Sensor W/ Complimentary Outputs |
INDUSTRY | APPLICATIONS |
Aviation/ Aerospace | Brake Controls, Jet Engines, Fuel Pump Monitor, APU, Turbochargers, Steering Mirror Actuator, Valve Actuator |
Biotech | Centrifuge Speed Measurement, Proximity Switches |
Exercise Equipment | Speed Control, Distance Measurement |
Military | Armored Fighting Vehicle, Amphibious Assault Vehicle, Unmanned Aerial Vehicles |
Railroad | Engine Controls, Turbines, Valve Position |