Ultrasonic sensor selection comes down to range, beam pattern, output type, and the acoustic environment. Ultrasonic sees what optical sensors cannot — clear film, dark plastic, mirror-finish parts — but it has its own failure modes (foam, soft surfaces, strong air currents).
Specs to confirm before ordering:
- Sensing range — short-range (5–30 cm), mid-range (20 cm to 1 m), long-range (1–10 m)
- Blind zone — the dead area near the transducer where detection is unreliable
- Beam angle — narrow beam for confined targets, wide beam for bulk-material level
- Output type: PNP/NPN switch, analog 0–10 V or 4–20 mA, IO-Link
- Teach/setpoint method: pushbutton, external teach wire, IO-Link parameters
- Mounting: M18, M30 barrel, rectangular block
- Environmental rating, including resistance to washdown and chemical splash
- Supply voltage (typically 10–30 VDC)
Common gotchas: foam, fabric, and soft insulation absorb the ultrasonic pulse and can return no echo at all — the sensor reports out-of-range even when a target is right in front of it. Strong air currents (from fans or compressed-air exhaust) deflect the pulse and add jitter. Two ultrasonic sensors aimed near each other can cross-talk; mid-range and long-range models often have a synchronization input to coordinate them. Temperature shifts change the speed of sound and shift readings — high-accuracy models include temperature compensation.
Typical applications: tank level on liquids, bins, and silos; height detection of dark or transparent bottles on conveyors; pallet position at stretch-wrap stations; loop control on web-fed material; and overhead crane positioning. On older lines, an exact replacement of the OEM ultrasonic sensor avoids re-aiming and re-teaching the setpoint to match the original mechanical layout.
For obsolete ultrasonic sensors, request a quote with the OEM number.
