Choosing the optimal speed sensor for an industrial or vehicle application requires matching the sensor’s underlying technology to your control architecture, physical mounting parameters, and available power supply. Speed sensors serve as the primary telemetry input for velocity regulation, requiring careful evaluation of four key selection criteria prior to system integration.
Power Availability (Passive vs. Active): Determine whether the installation point has access to auxiliary power. Magnetic pickup sensors operate passively without external voltage, producing an analog AC sine wave proportional to speed. If your receiving hardware requires an active digital pulse (NPN/PNP square wave) or needs to detect low rotational speeds (<500 RPM), select an active Hall effect sensor requiring a 5–30V DC power supply.
Measurement Target and Interface: For metallic gear teeth, tone wheels, or keyways, gear-tooth magnetic pickups or Hall sensors positioned within a 0.5 mm to 4.0 mm sensing gap deliver accurate tooth-by-tooth pulse signals. For non-contact vehicle speed measurement where no gear access exists, GPS pulse sensors eliminate mechanical wear entirely.
Mechanical Mounting and Enclosure Ratings: Match thread pitch and body length to your housing ports (e.g., standard M16, M18, or 5/8"-18 UNF threads). For cramped mounting spaces, choose compact flange-mount or slim cylindrical probe bodies. Ensure the enclosure provides at least IP67 ingress protection to prevent dust, oil, and moisture from compromising the sensing element.
Frequency and Output Signal Compatibility: Verify that the sensor’s maximum switching frequency (e.g., 10 Hz to 20 kHz) matches your maximum shaft RPM and target tooth count, and confirm that the output voltage amplitude aligns with your PLC counter module or ECU input specifications.