FAQ

What is an ultrasonic transducer?

An ultrasonic transducer is an electroacoustic device that converts electrical energy into ultrasonic sound waves. In many sensing systems, the same transducer also receives returning echoes and converts that acoustic energy back into an electrical signal.

In air-ranging and industrial sensing applications, ultrasonic transducers are commonly used to measure distance, detect objects, monitor level, or support flow measurement. The transducer is one of the most important components in the sensing system because its frequency, beam pattern, sensitivity, housing, and mechanical design directly affect performance.

How does an ultrasonic transducer work?

An ultrasonic transducer works by using a piezoceramic element. When an electrical pulse is applied, the piezoceramic element expands and contracts rapidly, creating ultrasonic sound waves. These sound waves travel through air or another medium until they reflect from a target surface. When the echo returns, pressure from the sound wave acts on the piezoceramic element and creates a small voltage signal that can be processed by the electronics.

What is a piezoceramic element?

A piezoceramic element is the active component inside many ultrasonic transducers. It is often shaped as a disk, bar, or ring, and a transducer may contain one element or multiple elements arranged in an array. The size, shape, and thickness of the piezoceramic element help determine the frequency at which the transducer operates.

What is the difference between an ultrasonic sensor and an ultrasonic transducer?

An ultrasonic transducer is the component that sends and receives the sound energy. An ultrasonic sensor is usually the complete device or system, which may include the transducer, housing, electronics, signal processing, outputs, and mounting hardware.

For OEMs and sensor manufacturers, the transducer is often the critical component that determines how well the finished sensor performs in the application.

What is the purpose of an ultrasonic transducer?

The purpose of an ultrasonic transducer is to generate and receive ultrasonic sound. In industrial applications, this allows a system to detect distance, level, object presence, flow conditions, or target position without physical contact.

Can ultrasonic transducers be used for level measurement?

Yes. Ultrasonic transducers are commonly used for non-contact level measurement of liquids, bulk solids, powders, and grains. The transducer sends a sound pulse toward the material surface and receives the reflected echo. The system then uses the echo timing to determine distance or level.

The application must be reviewed carefully because target surface, turbulence, foam, vapors, mounting angle, and range can affect performance.

Can ultrasonic transducers be used for open channel flow?

Yes. Ultrasonic transducers can be used in open channel flow applications, often as part of a system that measures level or flow-related distance. Several Parsonics transducer models list open channel flow as an application, including models designed with rugged housings and chemically resistant materials.

Can ultrasonic transducers be used in chemically aggressive environments?

Yes, when the transducer is designed with compatible materials. Parsonics offers transducers with housing materials such as Teflon, Kynar, PVC, CPVC, and stainless steel depending on the model and application. The PAR4012 Series specifically lists PVC or CPVC, Teflon, Kynar, and stainless steel as available housing materials.

Why does frequency matter in an ultrasonic transducer?

Frequency affects the way sound travels, the achievable sensing range, the beam pattern, the required drive electronics, and how the transducer responds to the target. Lower frequencies are often used for longer ranges because lower-frequency sound is generally less affected by attenuation. Higher frequencies may be useful for shorter-range applications where smaller size, tighter resolution, or a smaller target area is required.

For Parsonics, this is a good place to show examples without turning the FAQ into a catalog. For example, Parsonics transducers include models such as 14.6 kHz, 20 kHz, 40 kHz, 58 kHz, 75 kHz, and 200 kHz options across different ranges and housings.

Why does beam angle matter?

Beam angle determines how the ultrasonic energy spreads from the transducer. A narrow beam can help focus energy and improve target discrimination, but it may be more sensitive to target angle or uneven surfaces. A wider beam can help detect uneven or angled surfaces, but it may reduce target discrimination.

What is dead zone or blanking zone?

The dead zone, also called the blanking zone, is the area directly in front of the transducer where echoes cannot be reliably received. It is caused by transducer ringing, which is the continued vibration of the piezoelectric element after the excitation pulse ends.

This matters when the application requires close-range detection. If the target can move too close to the transducer face, the transducer and electronics must be selected carefully.