Fibre-optic hydrophones
The best instrument available to measure close to the face of the ultrasound transducer, make CW measurements or to measure the acoustic pressure and associated thermal effects of a high-intensity field.
Overview
The new fibre-optic hydrophone system is now available and features all the existing functions of its predecessor but with some notable improvements. These include a change to a more robust connector type that will improve the reliability of the system and provide the user a quicker setup before measurements with a simple ‘click in’ sensor input and less frequently required cleaning. Functionally, the system is now driven by an updated laser module with a wider tuning range which in turn will permit a greater range of temperature measurements. Furthermore, the system has a much improved software user interface.
For more information see the paper “A Fabry–Pérot fiber-optic ultrasonic hydrophone for the simultaneous measurement of temperature and acoustic pressure” in J. Acoust. Soc. Am, Vol. 125, No. 6, page 3611, June 2009.
The fibre optic hydrophone is the latest addition to our hydrophone range. Despite its 10 um active diameter the sensitivity is similar to larger element needle hydrophones. This, coupled with, its immunity from electro-magnetic radiation makes it particularly suited for high frequency measurements in hostile fields.
The system can be used in high intensity fields where needle or membrane hydrophones may experience serious damage. Replacement fibres are readily available and inexpensive.
The hydrophone can be used to measure temperature and pressure, at the same time, and at the same point in the field. This enables a direct correlation to be made between pressure and thermal change.
The fibre-optic hydrophone system is supplied with tapered tipped sensors which are optimised for optimal frequency response.
Fibre-optic hydrophone system
System supplied with fibres.
Tapered tip
Tapered fibre tip to ensure optimum frequency response over a wide frequency range.
Technical specifications
| Output impedance: | 50 Ω terminated system |
| Typical probe sensitivity: | tapered sensor 250 mV/MPa averaged in the range 2-20 MHz |
| Sensitivity tolerance: | Sensitivity variation between individual probes is approx. ±3 dB |
| Usable frequency range: | 250 kHz to 50 MHz (may require calibration at NPL, London for some frequency ranges) |
| Dynamic range: | 10 kPa to 15 MPa. Note the system has been tested in a field in excess of 700 Wcm-2 with no damage |
| Typical frequency response: | To be advised – please contact us |
| Sensor material: | 10 micron parylene on glass backing |
| Sensor dimension: | 10 micron diameter |
* Precision Acoustics reserves the right to change the specification without notice.
Software installation
The latest software is version FOH 1.2.0.27. If you need a copy of this file please email us
