HNP Series – Needle Hydrophones for Precise Ultrasound Field Measurements
The Onda HNP Series features compact needle hydrophones for spatially high-resolution characterization of ultrasonic fields. Thanks to their slim needle design, they allow pinpoint access to the measurement field while causing only minimal reflections within the acoustic field.
The HNP hydrophones connect a wide and flat frequency response with good directional characteristic and are particularly suited for laboratory applications, field mapping, and Doppler ultrasound measurements.
Broadband frequency response from 1 to 20 MHz
The HNP series offers a frequency range of 1 to 20 MHz (±6 dB). A piezopolymer is used as the sensor element, which enables a comparatively flat frequency response.
This enables reliable capture and analysis of broadband ultrasonic signals and complex acoustic fields. Compared to the more sensitive HNC needle hydrophones, the HNP series offers a flatter frequency response and a broader directional characteristic.
HNP-0200 and HNP-0400
Two models are available for different requirements regarding spatial resolution and sensitivity.
The HNP-0200 has an effective aperture of 200 µm and offers an acceptance angle of at 5 MHz 110°. Due to the small aperture, it is particularly suitable for spatially high-resolution field measurements.
The HNP-0400 has an aperture of 400 µm and achieves a higher nominal sensitivity. The acceptance angle at 5 MHz is 60°. This allows choosing between maximum spatial resolution and higher sensitivity depending on the measurement task.
Low influence on the ultrasonic field
The slender needle geometry of the HNP series features a low reflection profile. This minimizes the disturbance of the ultrasound field to be investigated by the hydrophone itself.
This property is particularly interesting in continuous ultrasound fields, where reflections and resulting interference patterns can affect the measurement. Therefore, Onda recommends needle hydrophones especially for corresponding CW applications.
Traceable calibration
The HNP hydrophones are equipped with a traceable calibration from 1 to 20 MHz delivered. Onda specifies calibration points for this at intervals of 50 kHz.
As a result, the frequency-dependent sensitivity of the respective hydrophone is available for quantitative sound pressure measurements. Further calibration ranges are also possible.
Typical applications
- Spatial mapping of ultrasonic fields
- Doppler ultrasound measurements
- Medical ultrasound technology
- Development and Characterization of Ultrasonic Transducers
- CW ultrasound applications
- Focused ultrasound fields
- Research and Development
- Quality assurance and calibration
Advantages of the HNP series
- Frequency range from 1 to 20 MHz
- Apertures of 200 and 400 µm
- Good spatial resolution
- Broad directional characteristic
- Flat frequency response
- piezopolymer sensor element
- Low acoustic reflection profile
- Compact needle design
- Traceable calibration
- Compatible with Onda preamplifiers and scanning systems
Onda HNP Series
The HNP series offers a compact and cost-effective solution for broadband ultrasonic field measurements. The combination of a small aperture, flat frequency response, and good directivity makes the hydrophones particularly attractive for applications that require high spatial resolution with minimal disturbance to the sound field.
Soliton supports you in selecting the suitable HNP hydrophone as well as the appropriate signal conditioning, calibration, and integration into automated ultrasonic measurement systems.
