where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -

596 views
Technical Discussions
Vaclav Stengl
Vaclav Stengl
07:08 Jan-24-2000
transducer - adjusting of tightness

Can somebody help me with where to find a how-to for adjusting the transducer voltage with a capacitor.


 
 Reply 
 
Robert (Rocky) A. Day
Engineering
Milky Way Jewels, USA, Joined Nov 1998, 40

Robert (Rocky) A. Day

Engineering
Milky Way Jewels,
USA,
Joined Nov 1998
40
06:21 Jan-25-2000
Re: transducer - adjusting of tightness
You probably are thinking of impedance matching networks sometimes put between the transducer and the pulser. Their purpose is to match the impedance of the pulser to that of the transducer which will produce maximum energy transfer between them. The impedance of the amplifier is usually neglected because during the pulse the protective diodes are very low impedance. I do not have many references in my library but the basic principles of impedance are usually covered in basic electronics textbooks.

I have an old book by Warren P. Mason 'Physical Acoustics and the Properties of Solids' with the a section on this subject. Section 3.3 titled 'Equivalent Circuits of Piezoelectric Crystals and Their Applications to Obtaining Maximum Energy Transfer.' Although this book was published in 1958 this is a solid exposition on this subject.

To quote this text 'By adding electrical or mechanical elements it is often possible to make the circuits into the form of filter sections which can be designed to match the electrical and mechanical conditions at the driving and receiving end.' This approach is not popular in NDT because in general it is difficult to obtain broadband filters without the use of active components. I know of one or two manufacturers who have at least experimented with active filters but they have not caught on in the market.

You can do a search of JASA and similar journals and find some more articles on this subject. The ultrasonic cleaning, impact grinding, sonoluminescence, and sonochemistry fields do use such matching networks. So you might look for articles in those areas as well.

Or maybe I have misinterpreted what you are looking for?

: Can somebody help me with where to find a how-to for adjusting the transducer voltage with a capacitor.




 
 Reply 
 

Product Spotlight

Combination of Digital Image Correlation and Thermographic Measurements

The combination of measuring results from the digital image correlation (ARAMIS, DIC) and temperat
...
ure measuring data from infrared cameras permits the simultaneous analysis of the thermal and mechanical behavior of test specimens in the materials and components testing field.
>

ISAFE3 Intrinsically Safe Sensor System

ISAFE3 intrinsically safe sensor system of Vallen Systeme is especially targeted at the petrochemica
...
l - as well as oil and gas transportation industry. The sensor system is designed for permanent monitoring or periodic inspection tasks. Sensors are available for different AE-frequency ranges optimized for corrosion and fatigue crack detection and other applications. The ISAFE 3 sensor system consists of an AE-sensor (model ISAS3) certified according to ATEX/IEC for installation in zone 0, gas group IIC, IP68, 20 to +60 °C, and a signal isolator (model SISO3) certified for installation in zone 2. An ISAS3 sensor can be mounted in atmosphere or submerged, e.g. in water or crude oil. It is supported by mounting tools for temporary (magnets) or permanent (welded) installation. ISAFE3 supports automatic sensor coupling test and can be used with any AE signal processor supporting 28V supply at 90 mA peak, e.g. Vallen Systeme ASIP-2/A.
>

Eddy Current inspection : RotoETscan Rotating Head

The rotating head RotoETscan detects the presence of longitudinal surface or sub surface defects a
...
t high speed. The rotating head is often installed directly on the production line. It is generally dedicated to the control of long products such as tubes, bars and wires, made of ferrous or non-ferrous material. It can also be used for inspection of small parts (billets).
>

Scatter Correction for Industrial Cone-Beam Computed Tomography (CBCT)

Download our white paper on Scatter Correction for Industrial Cone-Beam Computed Tomography (CBCT)
...
Using 3D VSHARP, a fast GPU-Based Linear Boltzmann Transport Equation Solver here: http://bit.ly/2Y0t78P
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window