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1821 views
01:55 Jul-06-1999
Serge Liberman
Ultrasonic Area-Scan Camera with RS-170 Interface?

Dear NDT experts,

I am looking for an ultrasonic camera that would allow me to measure distance from the transducer plane to the flat hard and rough surface of my sample. The camera should have a standard video interface, e.g. RS170 or NTSC, or PAL - anythign compatible with standard frame grabbers. The camera should report the distance to the sample surface as if it were image intensity.

The area that I need to inspect is about 3x3 cm, the depth resolution should be about 0.2 mm, the spatial resulution should be also be about 0.2 mm. The sample will be located parallel to
the camera plane at about 1 cm or closer.

I am new to the area of ultrasonic imaging - my area is data and image acquisition and processing - so I am sorry if I miss something basic.

I will appreciate any pointers to such products or anything even remotely similar to what I am looking for.

TIA,

-- Sergey


 
03:16 Jul-06-1999

Tom Nelligan

Engineering,
retired,
USA,
Joined Nov 1998
390
Re: Ultrasonic Area-Scan Camera with RS-170 Interface?
: Dear NDT experts,

: I am looking for an ultrasonic camera that would allow me to measure distance from the transducer plane to the flat hard and rough surface of my sample. The camera should have a standard video interface, e.g. RS170 or NTSC, or PAL - anythign compatible with standard frame grabbers. The camera should report the distance to the sample surface as if it were image intensity.

: The area that I need to inspect is about 3x3 cm, the depth resolution should be about 0.2 mm, the spatial resulution should be also be about 0.2 mm. The sample will be located parallel to
: the camera plane at about 1 cm or closer.

: I am new to the area of ultrasonic imaging - my area is data and image acquisition and processing - so I am sorry if I miss something basic.

: I will appreciate any pointers to such products or anything even remotely similar to what I am looking for.

: TIA,

: -- Sergey

Well, in the area of "remotely similar" products... they're not cameras as such, but many high frequency ultrasonic C-scan systems (including those made by my company) designed for imaging internal structures include time-based pulse/echo imaging capability that can also be used for surface profiling. When set up in that mode, the system records transit time to the first arriving echo from the surface, and it will produce an image that is color-coded with respect to reflector distance from the plane of the transducer, as you suggest.

What can be *very* tricky in many cases, however, is insuring that you're actually reading data from all of the relevant peaks and valleys. Transducer selection is important -- you need to work with a very sharp focus -- but even then, very sharply angled high points may not reflect any significant amount of energy, and narrow grooves likewise may not generate a usable reflection from the bottom. We usually recommend that resolution on a given surface be qualified experimentally, by scanning reference standards with known topography and comparing results. Depending on the extent and angulation of surface convolutions and the user's resolution requirements, the technique may or may not turn out to be appropriate.

--Tom Nelligan



 
01:21 Jul-07-1999

Robert A. Day

Engineering
Milky Way Jewels,
USA,
Joined Nov 1998
40
Re: Ultrasonic Area-Scan Camera with RS-170 Interface? Dear Serge -

I don't know of anything close to what you desire. The only UT video device I know of is the Solokov tube which is not commercially available and only reports the amplitude of the sound wave field rather than the distance. Distance is routinely measured from the time of flight of UT pulses, or less frequently from resonant swept frequency systems. The usual approach is to measure the time of flight with one transducer and scan the transducer over the area of interest. The other method is to build an array of 0.2 mm spaced transducers and electronically switch the transducers, an expensive proposition. Here is a brief tutorial and a system to do both.

Scanning -

The following assumes one transducer although more are feasable (4 to 16 being common).

Pulse-Echo
The travel time of the transducer assuming water with a velocity of 1.5 mm/microsec would be about 13 microseconds and represents the fastest update rate. In reality you might want to wait longer to avoid wrap around, reverberations from previous pulses, but in principle you can go this fast. This is a data rate of 75,000 Hz. A 3x3 cm area at 0.2 mm resolution requires 22,500 points to acquire one image which means that for water one transducer requires 0.3 seconds. Clearly we need some extra transducers to meet your video imaging requirement. Assuming 15 frames per second then 5 or more transducers would be required.

If air then the velocity is 0.3 mm/microsecond and the time of flight increases proportionally reducing the update rate to 15,000 Hz and we would need 25 transducers.

The cost of this type of equipment is about $2,000 per channel for units that update at 10 kHz so you would need a custom unit. Which may cost a little more.

Resonance
The resonant frequency for a 1 cm gap in water is 75 kHz. The existance of harmonics would allow us to use higher frequencies, 150, 300 kHz etc but as the gap changes it is possible to hop to another frequency. For example if 1 cm becomes 5 mm then the fundamental is 150 kHz and we would generate this frequency even though the gap is half what that frequency says. You can signal process your way out of this to an extent but if the gap changes much then extreme care is required. The best method to use is to move the transducer(s) to maintain the resonance and measure the movement instead of the actual frequency. Speed is limited by the time it takes to find the resonance. I'm guessing but I think it will be hard to design a system that can track in less than 5 cycles, 25 kHz at 75 kHz or 30 at 150 kHz etc. This still requires multiple transducers and systems.

Air would of course be 5 x slower for the same reasons as before.

Cost of this system is unknown, although it would be at least twice that of the pulse echo systems because no one is currently selling such systems. The systems that have been built are swept frequency systems that can make only 100 to 200 measurements per second and haven't been built in 20 years, although still in service here and there.

Arrays
An arrayof transducers with 0.2 mm resolution (150x150) elements is significantly beyond the state of the art. I currently make arrays of that size with 64 elements but the resolution is more like a mm at 1 cm. A phased array might do what you want. This is an array of transducers which are phased on transmit and receive in such a way to focus and steer the sound beam electronically. Video rates are still not possible for the reasons mentioned above unless multiple transducers are used. An array of arrays. The cost of a 16 x 16 element phased array is over $100,000 and multiple units would be required. I really don't see that this system buys you a lot in this case. The basic limitation is the speed of sound.

Tom Nelligan's comments on transducer selection are indeed right on. I have assumed a smooth surface, no sharp changes in profile of the target. Any sudden changes will destroy the signal and make it very difficult to measure the distance.

Regards,
Robert (Rocky) A. Day
Second Sound
Ultrasonic Systems
904 Cortland Avenue
San Francisco, CA 94110
(415) 641-4947
Fax: (415) 641-5502

: Dear NDT experts,

: I am looking for an ultrasonic camera that would allow me to measure distance from the transducer plane to the flat hard and rough surface of my sample. The camera should have a standard video interface, e.g. RS170 or NTSC, or PAL - anythign compatible with standard frame grabbers. The camera should report the distance to the sample surface as if it were image intensity.

: The area that I need to inspect is about 3x3 cm, the depth resolution should be about 0.2 mm, the spatial resulution should be also be about 0.2 mm. The sample will be located parallel to
: the camera plane at about 1 cm or closer.

: I am new to the area of ultrasonic imaging - my area is data and image acquisition and processing - so I am sorry if I miss something basic.

: I will appreciate any pointers to such products or anything even remotely similar to what I am looking for.

: TIA,

: -- Sergey




 
09:44 Jul-07-1999
Dipl.-Ing. Martin Heinz
Re: Ultrasonic Area-Scan Camera with RS-170 Interface? : Dear NDT experts,

: I am looking for an ultrasonic camera that would allow me to measure distance from the transducer plane to the flat hard and rough surface of my sample. The camera should have a standard video interface, e.g. RS170 or NTSC, or PAL - anythign compatible with standard frame grabbers. The camera should report the distance to the sample surface as if it were image intensity.

: The area that I need to inspect is about 3x3 cm, the depth resolution should be about 0.2 mm, the spatial resulution should be also be about 0.2 mm. The sample will be located parallel to
: the camera plane at about 1 cm or closer.

: I am new to the area of ultrasonic imaging - my area is data and image acquisition and processing - so I am sorry if I miss something basic.

: I will appreciate any pointers to such products or anything even remotely similar to what I am looking for.

: TIA,

: -- Sergey
Dear Sergey,

I think, what you search is an ultrasonic microscope like the ELSAM , manufactured by Leitz. We have
such a microscope in our institute. There the sample is placed into a measurement chamber, where
a coupling media like water must be present. Than the surface is scanned by high frequency ultrasound (20 MHz .. 2 GHz) with resolutions up to 50µm.
You can find more information on our internet page http://www.ibmt.fhg.de/public_e/Produktblaetter/pages/e_acoustic.htm .



 
01:29 Jul-07-1999

Linas Svilainis

R & D,
Kaunas University of Technology,
Lithuania,
Joined Nov 1998
67
Re: Ultrasonic Area-Scan Camera with RS-170 Interface? :...video interface, e.g. RS170...
:...area ...about 3x3 cm,
:..the depth resolution ...about 0.2 mm,
:..the spatial resolution ...about 0.2 mm.
:..The sample ... at about 1 cm or closer.

The similar system I know is FUSIS.
Of course, output data is not presenting the depth.
Here is some info I have on FUSIS system:
X,Y field: 128 x 128, 80 micron pixels
Scan time: 30 frames/second
X,Y resolution:0.08 mm to 1.0 mm, depending on lens position
Area coverage:1 cm to 12 cm, depending on lens position
Z Resolution: 0.15 mm in water
Sensitivity: 1 KPascal
Inspection mode: Transmission or reflection
Image mode: C-scan
Frequency range: 375 KHz to 20 MHz
Dynamic Range: 60 dB
Target contact: Liquid or pillow
Depth of field: 3 mm
Video Output: RS170, CCIR1
----------
The FUSIS system is best described as a camcorder for sound . Similar to a
conventional camcorder which is based on CCD technology sensitive to light,
Imperium has developed a novel 2D read out IC sensitive to ultrasound, not
light. The FUSIS technique can be used in either reflection (pulse-echo) or
transmission. Using FUSIS, the transmitter is separate from the novel IC
receiver. The system is broadband, working over a wide range of
frequencies.

A large area, uniform ultrasound beam insonifies the desired target. In the
reflection mode, the beam strikes the target and returns back towards the
sensor. An acoustic lens is used to collect the resulting beam and focus
the information onto the IC array.


FUSIS C-scan imaged in 1/30 second of corroded areas of an aluminum plate
The pattern formed strikes the ultrasound sensitive pixel elements (128 x
128) of the array. The voltage generated at each pixel is transferred to a
silicon CMOS multiplexer which is designed to read out the individual
voltages sequentially, producing a TV like image. Imperium has recently
been granted a patent on the read out IC array.

Signal processing provides range gating by controlling the acquisition
time of the array to occur when the ultrasound pulse generated by the source
transducer returns from a predetermined depth within the target (e.g. 5 mm
in depth). Each of the thirty frames per second can be programmed to return
from a different depth, providing 3D information (e.g. 3 mm to 8 mm, with 1
mm increments). Alternatively, at a single depth, the frames could be
integrated to provide enhanced signal to noise. The RS170 TV signal is then
frame grabbed and coupled to a standard machine vision system which performs
acceptance/rejection criteria, image enhancement, false color, image
annotation, etc.

The installation of the system could either be similar to traditional C-scan
systems by submerging targets in water and employing water squirter systems.
However, since FUSIS requires no mechanical scanning, the system will also
be implemented as a hand-held or mechanically driven probe with an
attached coupling pillow (similar to medical ultrasound imaging devices)
which gives immediate defect information and would not require targets to be
submerged in a fluid at all.

The only contact I can offer is Bob Lasser
(301) 330-7179,blasser@po.mctec.com

Good luck

Linas



 
02:35 Jul-07-1999
Wieslaw Bicz
Re: Ultrasonic Area-Scan Camera with RS-170 Interface?

: Dear NDT experts,

: I am looking for an ultrasonic camera that would allow me to measure distance from the transducer plane to the flat hard and rough surface of my sample. The camera should have a standard video interface, e.g. RS170 or NTSC, or PAL - anythign compatible with standard frame grabbers. The camera should report the distance to the sample surface as if it were image intensity.

: The area that I need to inspect is about 3x3 cm, the depth resolution should be about 0.2 mm, the spatial resulution should be also be about 0.2 mm. The sample will be located parallel to
: the camera plane at about 1 cm or closer.

: I am new to the area of ultrasonic imaging - my area is data and image acquisition and processing - so I am sorry if I miss something basic.

: I will appreciate any pointers to such products or anything even remotely similar to what I am looking for.

: TIA,

: -- Sergey

Dear Sergey,

It is possible to use our holographic ultrasonic camera for this purpose (see please http://www.optel.com.pl/article/english/article.htm).
The resolution and the scanning area would be even larger, the price about 6000 Euro and the measuring time about 1 second. It is even possible to make such camera with the measuring time about 1/30 second or even higher (1000 measurements per second are possible).

If you could send us a sample, we can make the measurements and send you the results.

The standard version of this device uses PC card or centronics interface.
Other interfaces are possible. RS would be - I think - to slow.

Your sincerely

Wieslaw Bicz

Optel sp. z o.o.

http://www.optel.com.pl



 
06:16 Jul-10-1999
Serge Liberman
Re: Ultrasonic Area-Scan Camera - Thanks! Dear experts,

Thanks to all of you for answering my question - I've got some very promising leads; now I have something to start from.

-- Serge Liberman



 
09:29 Aug-31-1999
Wolfgang Bisle
Re: Ultrasonic Area-Scan Camera with RS-170 Interface? I don't know, if they will be the right address but I had recently
contact with Prof. Maev from the
University of Windsor/Chrysler Canada Ltd.
Center of Imaging Research and Advanced Materials Characterization
(http://www2.uwindsor.ca/~maev/centre3.html and e-mail: maev@uwindsor.ca)
They do the developement of arrays and also developement of
high speed 2D and 3D image processing systems for these applications.
Maybe this is an address which can give you more....
Look for his homepage.

Wolfgang Bisle


: : Dear NDT experts,

: : I am looking for an ultrasonic camera that would allow me to measure distance from the transducer plane to the flat hard and rough surface of my sample. The camera should have a standard video interface, e.g. RS170 or NTSC, or PAL - anythign compatible with standard frame grabbers. The camera should report the distance to the sample surface as if it were image intensity.

: : The area that I need to inspect is about 3x3 cm, the depth resolution should be about 0.2 mm, the spatial resulution should be also be about 0.2 mm. The sample will be located parallel to
: : the camera plane at about 1 cm or closer.

: : I am new to the area of ultrasonic imaging - my area is data and image acquisition and processing - so I am sorry if I miss something basic.

: : I will appreciate any pointers to such products or anything even remotely similar to what I am looking for.

: : TIA,

: : -- Sergey

: Well, in the area of "remotely similar" products... they're not cameras as such, but many high frequency ultrasonic C-scan systems (including those made by my company) designed for imaging internal structures include time-based pulse/echo imaging capability that can also be used for surface profiling. When set up in that mode, the system records transit time to the first arriving echo from the surface, and it will produce an image that is color-coded with respect to reflector distance from the plane of the transducer, as you suggest.

: What can be *very* tricky in many cases, however, is insuring that you're actually reading data from all of the relevant peaks and valleys. Transducer selection is important -- you need to work with a very sharp focus -- but even then, very sharply angled high points may not reflect any significant amount of energy, and narrow grooves likewise may not generate a usable reflection from the bottom. We usually recommend that resolution on a given surface be qualified experimentally, by scanning reference standards with known topography and comparing results. Depending on the extent and angulation of surface convolutions and the user's resolution requirements, the technique may or may not turn out to be appropriate.

: --Tom Nelligan
:




 
06:14 Oct-03-1999
Javad Sadaie
Re: Ultrasonic Area-Scan Camera with RS-170 Interface? : :...video interface, e.g. RS170...
: :...area ...about 3x3 cm,
: :..the depth resolution ...about 0.2 mm,
: :..the spatial resolution ...about 0.2 mm.
: :..The sample ... at about 1 cm or closer.

: The similar system I know is FUSIS.
: Of course, output data is not presenting the depth.
: Here is some info I have on FUSIS system:
: X,Y field: 128 x 128, 80 micron pixels
: Scan time: 30 frames/second
: X,Y resolution:0.08 mm to 1.0 mm, depending on lens position
: Area coverage:1 cm to 12 cm, depending on lens position
: Z Resolution: 0.15 mm in water
: Sensitivity: 1 KPascal
: Inspection mode: Transmission or reflection
: Image mode: C-scan
: Frequency range: 375 KHz to 20 MHz
: Dynamic Range: 60 dB
: Target contact: Liquid or pillow
: Depth of field: 3 mm
: Video Output: RS170, CCIR1
: ----------
: The FUSIS system is best described as a camcorder for sound . Similar to a
: conventional camcorder which is based on CCD technology sensitive to light,
: Imperium has developed a novel 2D read out IC sensitive to ultrasound, not
: light. The FUSIS technique can be used in either reflection (pulse-echo) or
: transmission. Using FUSIS, the transmitter is separate from the novel IC
: receiver. The system is broadband, working over a wide range of
: frequencies.

: A large area, uniform ultrasound beam insonifies the desired target. In the
: reflection mode, the beam strikes the target and returns back towards the
: sensor. An acoustic lens is used to collect the resulting beam and focus
: the information onto the IC array.

:
: FUSIS C-scan imaged in 1/30 second of corroded areas of an aluminum plate
: The pattern formed strikes the ultrasound sensitive pixel elements (128 x
: 128) of the array. The voltage generated at each pixel is transferred to a
: silicon CMOS multiplexer which is designed to read out the individual
: voltages sequentially, producing a TV like image. Imperium has recently
: been granted a patent on the read out IC array.

: Signal processing provides range gating by controlling the acquisition
: time of the array to occur when the ultrasound pulse generated by the source
: transducer returns from a predetermined depth within the target (e.g. 5 mm
: in depth). Each of the thirty frames per second can be programmed to return
: from a different depth, providing 3D information (e.g. 3 mm to 8 mm, with 1
: mm increments). Alternatively, at a single depth, the frames could be
: integrated to provide enhanced signal to noise. The RS170 TV signal is then
: frame grabbed and coupled to a standard machine vision system which performs
: acceptance/rejection criteria, image enhancement, false color, image
: annotation, etc.

: The installation of the system could either be similar to traditional C-scan
: systems by submerging targets in water and employing water squirter systems.
: However, since FUSIS requires no mechanical scanning, the system will also
: be implemented as a hand-held or mechanically driven probe with an
: attached coupling pillow (similar to medical ultrasound imaging devices)
: which gives immediate defect information and would not require targets to be
: submerged in a fluid at all.

: The only contact I can offer is Bob Lasser
: (301) 330-7179,blasser@po.mctec.com

: Good luck

: Linas




 
08:02 Sep-27-2000
k.haribabu
Re: Ultrasonic Area-Scan Camera with RS-170 Interface? : : Dear NDT experts,

: : I am looking for an ultrasonic camera that would allow me to measure distance from the transducer plane to the flat hard and rough surface of my sample. The camera should have a standard video interface, e.g. RS170 or NTSC, or PAL - anythign compatible with standard frame grabbers. The camera should report the distance to the sample surface as if it were image intensity.

: : The area that I need to inspect is about 3x3 cm, the depth resolution should be about 0.2 mm, the spatial resulution should be also be about 0.2 mm. The sample will be located parallel to
: : the camera plane at about 1 cm or closer.

: : I am new to the area of ultrasonic imaging - my area is data and image acquisition and processing - so I am sorry if I miss something basic.

: : I will appreciate any pointers to such products or anything even remotely similar to what I am looking for.

: : TIA,

: : -- Sergey

: Dear Sergey,

: It is possible to use our holographic ultrasonic camera for this purpose (see please http://www.optel.com.pl/article/english/article.htm).
: The resolution and the scanning area would be even larger, the price about 6000 Euro and the measuring time about 1 second. It is even possible to make such camera with the measuring time about 1/30 second or even higher (1000 measurements per second are possible).

: If you could send us a sample, we can make the measurements and send you the results.

: The standard version of this device uses PC card or centronics interface.
: Other interfaces are possible. RS would be - I think - to slow.

: Your sincerely

: Wieslaw Bicz

: Optel sp. z o.o.

: http://www.optel.com.pl




 
08:09 Sep-27-2000
k.haribabu
RS-170 Interface ccd camera & dsp processor to rs-170 how to interface ccd colour camera (pulnix tmc9700)& dsp processor to rs-170 cable & what are the properties are used in interfacing this components . plese send the information to my e-mail address.


 
08:27 Mar-15-2002
Vikas Mummigatti
Re: RS-170 Interface ccd camera & dsp processor to rs-170 : how to interface ccd colour camera (pulnix tmc9700)& dsp processor TMS320C6201 & what are the properties are used in interfacing this components . plese send the information to my e-mail address.




 


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