HM Series – Broadband Membrane Hydrophones for Precise Ultrasonic Measurements
The HM series from Onda includes broadband membrane hydrophones for the precise measurement of pulsed and continuous ultrasonic fields in liquids. The planar membrane design enables a very uniform frequency response and high sensitivity over a wide frequency range.
This makes the hydrophones suitable for the characterization of medical ultrasound systems as well as for research, development, calibration, and demanding acoustic field measurements.
Planar diaphragm for broadband measurements
The central element of the HM series is a thin piezoelectric membrane that responds to acoustic pressure fluctuations. The planar design enables a broadband and comparatively flat frequency response and is therefore particularly suitable for the reproducible acquisition of complex ultrasonic pulses.
Depending on the model and configuration, the HM series covers a wide frequency range, thereby enabling the characterization of a wide variety of ultrasonic sources.
HMA – free membrane for high sound pressure levels
The HMA designs use a freely tensioned membrane without rear acoustic support. This construction reduces additional interactions with a rear wall and is particularly suitable for applications with high acoustic pressure amplitudes.
HMA hydrophones are thus an interesting solution for demanding field measurements and applications involving high sound pressure levels.
HMB-supported membrane for high stability
At the HMB versions the membrane is mechanically supported. This increases its robustness against mechanical stress, for example from water movement or during automated measurement procedures.
The supported membrane construction combines high sensitivity with good mechanical stability, making it particularly suitable for repeated measurements and automated hydrophone scanning systems.
Different apertures for various measurement tasks
The HM series is available with different active apertures available. This allows the trade-off between sensitivity and spatial resolution to be tailored to the specific measurement task.
Smaller apertures enable higher spatial resolution, for example in focused ultrasound fields. Larger apertures offer higher sensitivity and are accordingly suitable for measurements of lower sound pressure levels.
Traceable calibration
For quantitative sound pressure measurements, Onda offers the HM hydrophones with traceable calibration Thus, the frequency-dependent sensitivity of the respective hydrophone can be taken into account during evaluation.
The HM series is therefore suitable both for general field mapping and for applications with high demands on the reproducibility and comparability of measurement results.
Typical applications
- Medical ultrasound technology
- Characterization of ultrasonic transducers
- Acoustic field measurement
- Pulsed ultrasound measurements
- Automated hydrophone scanning systems
- Research and Development
- Quality assurance
- Calibration and reference measurements
Advantages of the HM Series
- broadband diaphragm construction
- Flat frequency response
- High sensitivity
- Different aperture sizes available
- HMA with free membrane
- HMB with mechanically supported membrane
- Good spatial resolution
- Traceable calibration
- Suitable for automated measuring systems
- Different designs for various ultrasound applications
HM series from Onda
The HM series offers a flexible platform for precise and broadband ultrasonic measurements. With various apertures and free or supported membrane designs, the hydrophones can be specifically tailored to requirements regarding sensitivity, spatial resolution, sound pressure, and mechanical robustness.
Soliton supports you in selecting the appropriate HM hydrophone as well as the matching calibration, signal conditioning, and integration into your ultrasonic measurement system.
