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Ultrasonic signal amplification and noise in a crystal of CdS
t3oacY,
vyuoov,
R. B.
The use of ultrasonics in fatigue Evaluation, 22, No. 11, 509 (1964)
testing.
Materials
P. M.
and GUMANYUK,
v. s.
temperature ultrasonic interferometer. Fizicheskii Zhurnal, 9, No. 7, 766 (1964) High
Ukrainskii
Apart from the wide use of ultrasonics for flaw detection or the onset of fatigue cracks, it can also be used to study fatigue itself. The study is based predominantly on the measured changes in attenuation and velocity as the specimen is cycled in a suitable machine. Pulse-echo or transmission techniques with longitudinal or surface waves can be used. It has been found that the onset of microcracks can best be detected during the extension cycle but the growth of fatigue cracks can also be followed and from their rate of propagation, fundamental properties of the material being tested can be inferred. After a brief introduction to the subject a case history of testing different diameter pipes is given (11 figures, 34 references)
A novel interferometer arrangement permits the measurement of velocity in materials in the liquid state up to 2000°C. A solid rod of the material whose velocity is to be determined slide fits into a temperature graded furnace from below. The upper end of this rod is melted, while the lower end, to which the piezoelectric transducer is coupled, is water-cooled. A ceramic reflector fixed to a micrometer from above can be moved up and down inside the molten zone of the material. The liquid/solid boundary does not seem to influence the accuracy of measurement, which is of the order of 0.2 % (1 figure, 1 table, 7 references) (Uftrasonics
(Ultrasonics
WIESNER,
1965, abstract
357)
Society of America,
Drying processes can be considerably accelerated and the final moisture content reduced by a pneumatic Hartmanntype high frequency sound generator. It can be used independently or in conjunction with conventional drying installations and is particularly suitable for drying heatsensitive or special materials. The air displacement is some 1000 times greater than in rotary dryers and at 165 dB the pressure varies by f 11% above and below atmospheric, The driving air is separated from the sound field, which prevents turbulence and contamination of the drying material (6 figures, 1 table, 12 references) (Ultrasonics 1965, abstract 358)
THALER,
W. J.
Frequency modulation of an He-Ne laser beam via ultrasonic waves in quartz crystal. Applied Physics Letters, 5, No. 2, 29 (1964)
Light waves or laser beams can be frequency modulated by an orthogonally propagated plane progressive ultrasonic wave. The ultrasonic modulation cells could be cascaded to continuously vary the frequency of the incident laser beam over any significant frequency range. An experimental set up is described for the detection of laser frequency modulation which uses X-cut quartz crystals operating at resonance between 0.4 MC/S and 10 MC/S. At 10 MC/S as little as 50 mW average ultrasonic power could be detected and at 50 W the crystal produced diffraction orders k = f 10 (2 figures, 5 references) (Uhrasonics 1965, abstract 359)
VASKOVA,
V. I.
E. P.
Multi-channel delay line increases memory Electrical Design News, 9, No. 9, 56 (1964)
SOLOFF, R. S.
Sonic dsylng. Journal of the Acoustical 36, No. 5, 961 (1964)
1965, abstract 361)
et cd.
Ultrasonic signal amplification and noise in a crystal of CdS. Akusticheski Zhurnal, 10, No. 4, p. 403 (1964)
Preliminary results are given of an experimental investigation to determine the influence of noise in cadmium sulphide crystals on the amplification factor. A 12.3 mm Cds crystal of conductivity 6.5 x 10m5Q-i cm-l was used at 2857 V/cm. 1 MC/S shear wave pulses generated by a Y-cut quartz crystal were propagated perpendicularly to the axis of the hexagon. A maximum gain of 35 dB has been achieved, adverse effect of noise on amplification has been confirmed and a “kink” or negative amplification at certain forward potentials has been observed (3 figures, 2 tables, 7 references) (Ultrasonics 1965, abstract 360)
capacity.
A number of information channels can be interlaced in a single delay line to increase its capacity. Maximum data can be stored even when the clock rate of the system is many times less than the speed of the line. A high speed printer based on this delay line idea has also been produced. (2 diagrams, 1 photograph) (Ultrasonics 1965, abstract 362) Usomat-a new ultrasonic testing instrument. Digest, 7, No. 1, 69 (1965)
Technical
A twin probe continuous wave transmission flaw detector particularly suitable for testing joints of materials of different acoustic impedances has been developed. To overcome resonance effects, the transmitter is frequency modulated and the plastics tipped probes are pneumatically operated to ensure a good acoustic contact without any coupling fluid. Reproducible positioning of the probes, acceptance level settings and a host of accessories make the instrument suitable for full automatic programming, particularly for small objects such as welded switchgear components. Usomat works at 4 MC/S, weighs 35 kg and can detect discontinuities of 1 mm diameter. Sixty joints can be recorded per minute (4 figures) (Ultrasonics 1965, abstract 363) Ultrasonic success.
Electronics,
37, No. 26, 29 (1964)
Ultrasound-guided forceps have been used to remove a piece of brass from a blood-clouded human eye in 39 set: the eye was saved. The ultrasonic retrieval probe, 2 mm across by 12 mm long, consists of a 1 mm diameter ceramic transducer mounted behind the tips of miniature eye forceps. After the foreign object has been located approximately by the pulse-echo method the forceps-probe is introduced into the eye and the relative position of probe and object can be monitored on an A-scan. The whole equipment can be sterilized. The power level can be varied from 0.1 mW to 10 mW and frequency from 1 MC/S to 10 MC/S at 200 p/s. No harmful effects on the eye have been observed and the equipment with different probes can be used for other applications (2 photographs) (Ultrasonics 1965, abstract
364)
Sonics unite with magnetic glow for automatic testing. Iron Age, 194, No. 16, 55 (1964)
billet
An automatic testing installation combines ultrasonics with magnetic particle methods to find internal and external defects in steel billets of any cross-section up to 40 ft long. Two high speed scanning transducers at 90” to each other are liquid column coupled to the billet: defects can be marked automatically or manually. The next part of the conveyer line contains the magnetic particle installation, where a computer grades the billets and moves them into four separate compartments according to quality (4 references, 1 table) (Ultrasonics 1965, abstract 365)
ULTRASONICS/
April-June
1965
vyuoov,
R. B.
The use of ultrasonics in fatigue Evaluation, 22, No. 11, 509 (1964)
testing.
Materials
P. M.
and GUMANYUK,
v. s.
temperature ultrasonic interferometer. Fizicheskii Zhurnal, 9, No. 7, 766 (1964) High
Ukrainskii
Apart from the wide use of ultrasonics for flaw detection or the onset of fatigue cracks, it can also be used to study fatigue itself. The study is based predominantly on the measured changes in attenuation and velocity as the specimen is cycled in a suitable machine. Pulse-echo or transmission techniques with longitudinal or surface waves can be used. It has been found that the onset of microcracks can best be detected during the extension cycle but the growth of fatigue cracks can also be followed and from their rate of propagation, fundamental properties of the material being tested can be inferred. After a brief introduction to the subject a case history of testing different diameter pipes is given (11 figures, 34 references)
A novel interferometer arrangement permits the measurement of velocity in materials in the liquid state up to 2000°C. A solid rod of the material whose velocity is to be determined slide fits into a temperature graded furnace from below. The upper end of this rod is melted, while the lower end, to which the piezoelectric transducer is coupled, is water-cooled. A ceramic reflector fixed to a micrometer from above can be moved up and down inside the molten zone of the material. The liquid/solid boundary does not seem to influence the accuracy of measurement, which is of the order of 0.2 % (1 figure, 1 table, 7 references) (Uftrasonics
(Ultrasonics
WIESNER,
1965, abstract
357)
Society of America,
Drying processes can be considerably accelerated and the final moisture content reduced by a pneumatic Hartmanntype high frequency sound generator. It can be used independently or in conjunction with conventional drying installations and is particularly suitable for drying heatsensitive or special materials. The air displacement is some 1000 times greater than in rotary dryers and at 165 dB the pressure varies by f 11% above and below atmospheric, The driving air is separated from the sound field, which prevents turbulence and contamination of the drying material (6 figures, 1 table, 12 references) (Ultrasonics 1965, abstract 358)
THALER,
W. J.
Frequency modulation of an He-Ne laser beam via ultrasonic waves in quartz crystal. Applied Physics Letters, 5, No. 2, 29 (1964)
Light waves or laser beams can be frequency modulated by an orthogonally propagated plane progressive ultrasonic wave. The ultrasonic modulation cells could be cascaded to continuously vary the frequency of the incident laser beam over any significant frequency range. An experimental set up is described for the detection of laser frequency modulation which uses X-cut quartz crystals operating at resonance between 0.4 MC/S and 10 MC/S. At 10 MC/S as little as 50 mW average ultrasonic power could be detected and at 50 W the crystal produced diffraction orders k = f 10 (2 figures, 5 references) (Uhrasonics 1965, abstract 359)
VASKOVA,
V. I.
E. P.
Multi-channel delay line increases memory Electrical Design News, 9, No. 9, 56 (1964)
SOLOFF, R. S.
Sonic dsylng. Journal of the Acoustical 36, No. 5, 961 (1964)
1965, abstract 361)
et cd.
Ultrasonic signal amplification and noise in a crystal of CdS. Akusticheski Zhurnal, 10, No. 4, p. 403 (1964)
Preliminary results are given of an experimental investigation to determine the influence of noise in cadmium sulphide crystals on the amplification factor. A 12.3 mm Cds crystal of conductivity 6.5 x 10m5Q-i cm-l was used at 2857 V/cm. 1 MC/S shear wave pulses generated by a Y-cut quartz crystal were propagated perpendicularly to the axis of the hexagon. A maximum gain of 35 dB has been achieved, adverse effect of noise on amplification has been confirmed and a “kink” or negative amplification at certain forward potentials has been observed (3 figures, 2 tables, 7 references) (Ultrasonics 1965, abstract 360)
capacity.
A number of information channels can be interlaced in a single delay line to increase its capacity. Maximum data can be stored even when the clock rate of the system is many times less than the speed of the line. A high speed printer based on this delay line idea has also been produced. (2 diagrams, 1 photograph) (Ultrasonics 1965, abstract 362) Usomat-a new ultrasonic testing instrument. Digest, 7, No. 1, 69 (1965)
Technical
A twin probe continuous wave transmission flaw detector particularly suitable for testing joints of materials of different acoustic impedances has been developed. To overcome resonance effects, the transmitter is frequency modulated and the plastics tipped probes are pneumatically operated to ensure a good acoustic contact without any coupling fluid. Reproducible positioning of the probes, acceptance level settings and a host of accessories make the instrument suitable for full automatic programming, particularly for small objects such as welded switchgear components. Usomat works at 4 MC/S, weighs 35 kg and can detect discontinuities of 1 mm diameter. Sixty joints can be recorded per minute (4 figures) (Ultrasonics 1965, abstract 363) Ultrasonic success.
Electronics,
37, No. 26, 29 (1964)
Ultrasound-guided forceps have been used to remove a piece of brass from a blood-clouded human eye in 39 set: the eye was saved. The ultrasonic retrieval probe, 2 mm across by 12 mm long, consists of a 1 mm diameter ceramic transducer mounted behind the tips of miniature eye forceps. After the foreign object has been located approximately by the pulse-echo method the forceps-probe is introduced into the eye and the relative position of probe and object can be monitored on an A-scan. The whole equipment can be sterilized. The power level can be varied from 0.1 mW to 10 mW and frequency from 1 MC/S to 10 MC/S at 200 p/s. No harmful effects on the eye have been observed and the equipment with different probes can be used for other applications (2 photographs) (Ultrasonics 1965, abstract
364)
Sonics unite with magnetic glow for automatic testing. Iron Age, 194, No. 16, 55 (1964)
billet
An automatic testing installation combines ultrasonics with magnetic particle methods to find internal and external defects in steel billets of any cross-section up to 40 ft long. Two high speed scanning transducers at 90” to each other are liquid column coupled to the billet: defects can be marked automatically or manually. The next part of the conveyer line contains the magnetic particle installation, where a computer grades the billets and moves them into four separate compartments according to quality (4 references, 1 table) (Ultrasonics 1965, abstract 365)
ULTRASONICS/
April-June
1965