Selection guide
Open-face vs closed-face ultrasonic transducers
The appropriate construction depends on acoustic goals, exposure, mounting, service life, and the total cost of making the sensor dependable in your product.
| Design factor | Open face | Closed face |
|---|---|---|
| Acoustic path | Exposed diaphragm with direct coupling to air | Protected acoustic surface or enclosure construction |
| Environmental exposure | Best where contamination and moisture are controlled | Often considered where additional physical protection is needed |
| Integration | Enclosure and mounting design can strongly affect performance | Mechanical interfaces and face materials remain important |
| Typical tradeoff | Potentially strong acoustic response with more exposure | Protection balanced against acoustic and packaging requirements |
| Validation | Test the complete assembly across temperature, humidity, contamination, mounting variation, target conditions, and electrical tolerances. | |
Start with the environment
Protection is a system decision
A closed-face part may be a better starting point for exposed equipment, but its construction does not automatically certify the finished assembly for a particular ingress or environmental rating. Likewise, an open-face element can work well inside a properly engineered enclosure.
Define how the transducer, seals, housing, adhesives, electronics, and manufacturing process work together.
Start with the target
Acoustics determine feasibility
Distance alone is not enough. Target material, size, angle, movement, nearby geometry, desired beam width, temperature, and airflow can materially change the echo.
Prototype early with representative targets and a realistic mechanical assembly.
Selection checklist
Information that helps us recommend a direction
- Minimum and maximum sensing distance
- Target material, dimensions, orientation, and speed
- Operating temperature, moisture, dust, chemicals, and airflow
- Available mounting space and desired field of view
- Transmit voltage, receive electronics, and timing constraints
- Prototype and annual production quantities
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