R Y D E R , F.L. M~gnetostricUve liquid-level sensors. I.S.A. Transactions, 6, No. 1, p. 1 (1967). The design of magnetostrictive liquid-level gauges are discussed. Analyses of mechanical vibrations, magnetic circuits, magnetostrictive behaviour and electronics are given. A number of equations are devised to emphasize the significantvariables in the design of practical installations. The techniques reported here should also prove of interest in laboratory experiments. (4 figures, 3 references) (Ultrasonics 1967, abstract 670)
Ultrasonic engineering equipment. Light Production Engineering, 5, Nos. 2 & 3, pp. 10 & 30 (1967). A two-part survey in consecutive issues of the journal on the latestapplications of ultrasonics in industry. Part one surveys cleaning, flaw detection, thickness and hardness measuring: part 2 concludes with ultrasonic welding of metals and plastics, machining, soldering and the application of ultrasonics to proximity sensors and leak detection. A table of ultrasonically weldable material combinations and a list of 27 companies in the U.K. supplying ultrasonic equipment is also given. (Ultrasonics 1967, abstract 676)
SAKIOTIS, N. Acoustic delay lines. International Electronics, 13, No. i, p. 48 (1967). Recent advances in the development of thin film piezoelectric semiconductors have produced low loss transducers that can operate well into the gigahertz frequency range. This article is a review of the latest developments in ultrasonic delay lines, bulk-effect amplifiers and other ultrasonic devices to operate at high frequencies. (4 figures) (Ultrasonics 1967, abstract 671)
M e a s u r i n g h a r d n e s s by u l t r a s o n i c s . E l e c t r i c a l Review, 160, No. 9, p. 323 (1967). A d e s c r i p t i o n of the Sonodur m i c r o h a r d n e s s t e s t i n g equipment. The s u r f a c e h a r d n e s s of a wide r a n g e of m a t e r i a l s c a n be r e g i s t e r e d d i r e c t l y on a dial o r the p r o c e s s can be autom a t e d in a g o / n o - g o f o r m on a p r o d u c t i o n line. The i n d e n t e r weighs only 150gm so the s i z e of indentation is negligible. E q u i p m e n t can be c a l i b r a t e d in Rockwell u n i t s in the r a n g e of 20--70 with.an a c c u r a c y of +1 unit. F u t u r e a p p l i c a t i o n s of t h i s t e c h n i q u e m i g h t include the m e a s u r e m e n t of Young's modulus, s t r a i n , c r e e p and m e t a l fatigue. (3 f i g u r e s ) ( U l t r a s o n i c s 1967, a b s t r a c t 677)
S E L M E R , R. H. and B E R G E R , H. Comparisons between ultrasonic inspection systems-mechanical scan versus television imaging. Materials Evaluation, 25, No. 4, p. 91 (1967). The relative merits of the two inspection techniques are compared. This study was predominantly concerned with the non-destructive testing of flat reactor-fuel plates. R has been found that the mechanical scanning system is more adaptable and can better discriminate between the various types of defects. The ultrasonic camera can detect smaller discontinuities and can operate at much higher speeds. (I0 figures, 15 references) (Ultrasonics 1967, abstract 672)
SNOW'DEN, P. P. and W A R N E , B. P. G. Ultrasonic testing in large steel works. British Journal of Non-destructive Testing, 9, No. 1, p. 2 (1967). A detailed description of the procedures in testing rolled billets,rotor shafts and turbine discs. The need for defect/ acceptance standards is emphasized. It is felt that the very high sensitivity standards practiced in industry are not always justifiable on economic grounds. M o r e work to determine the effects of the various types of defect in service is indicated. (10 figures, 4 references) (Ultrasonics 1967, abstract 673)
S T E V E N S O N , T. J. Two-terminal drive circuit for a piezo-electricaily driven mechanical vibrator. Electronic Engineering, 39, No. 470, p. 222 (1967). A simple transistorized circuit has been developed to drive a mechanical vibrator with a simple piezoelectric transducer at resonance. Oscillations are controlled by the mechanical resonance. The circuit does not require inductive elements and the capacitance of the transducer can be neglected. The component values are not critical and are highly variable to suit any given application. (6 figures) (Ultrasonics 1967, abstract 674)
U l t r a s o n i c s t a k i n g w o r k s well in joining p l a s t i c s . P r o d u c t E n g i n e e r i n g , 38, No. 1, p. 79 (1967). U l t r a s o n i c s t a k i n g is about twice as f a s t a s the conventional heating method and the t e m p e r a t u r e p r o d u c e d is too low to m e l t o r d e g r a d e the m a t e r i a l . It can join p l a s t i c s to m e t a l o r any o t h e r m a t e r i a l in a f r a c t i o n of a second. The weld cycle can be m e c h a n i z e d to p r o d u c e u n i f o r m and c o n s i s t e n t r e s u l t s . Up to now the m i n i m u m stud d i a m e t e r h a s been a p p r o x i m a t e l y 3/sin (9.5 ram) but new d e v e l o p m e n t s p r o m i s e s u b m i n i a t u r e staking f o r u s e in m i c r o e l e c t r o n i c c i r c u i t s . (1 figure) ( U l t r a s o n i c s 1R67, a b s t r a c t 678)
E a r s need p r o t e c t i o n f r o m u l t r a s o n i c s too. Safety M a i n tenance, 133, No. 1, p. 4 (1967). The inaudible r a n g e of n o i s e s g e n e r a t e d by i n d u s t r y and h o s pital equipment can c a u s e l o s s of h e a r i n g . A c c o r d i n g to this p a p e r the d e t e r i o r a t i o n of h e a r i n g is i m p e r c e p t i b l y slow and the d a m a g e cannot be r e p a i r e d . Among o t h e r s h o s p i t a l equipm e n t s such as ultrasonic cleaners and diagnostic and surgicai equipment are singled out for criticism. Some safety measures and precautions against exposure to high frequency sound are mentioned. (I figure) (Ultrasonics 1967, abstract 679)
E l e c t r o n i c s f i n d s new u s e s , f r o m C - D ignition s y s t e m s to piston t e m p e r a t u r e m e a s u r e m e n t . Society of Autom o t i v e E n g i n e e r s J o u r n a l , 75, No. 1, p. 45 (1967). The s i z e of the e c h o e s of u l t r a s o n i c s u r f a c e waves is a r e l i able indication of the quality of c o n t r a s t between the p i s t o n r i n g and the c y l i n d e r bore. The condition of m u l t i - r i n g p i s t o n s of d i f f e r e n t shapes, including d o u b l e - r a i l e d a n d / o r landed r i n g s can be evaluated. With s u i t a b l e r e c o r d i n g equipm e n t p e r m a n e n t r e c o r d s can be m a d e for m o n i t o r i z i n g the p r o c e s s of w e a r of any component. (3 f i g u r e s ) ( U l t r a s o n i c s 1967, a b s t r a c t 680)
U l t r a s o n i c e n e r g y aids tube drawing. M a c h i n e r y , 73,
WELLS, P. N. T. Signal p r o c e s s i n g in t w o - d i m e n s i o n a l u l t r a s o n o g r a p h y . Biomedical Engineering, 2, No. 4, p. 165 (1967). Some b a s i c p r i n c i p l e s of conventional t w o - d i m e n s i o n a l u l t r a sonic pulse echo s c a n n i n g and r e c o r d i n g techniques a r e d i s cussed. The v a r i o u s f a c t o r s which d e t e r m i n e the choice of u l t r a s o n i c f r e q u e n c y and s o m e s i g n a l p r o c e s s i n g c i r c u i t s to f a c i l i t a t e the i n t e r p r e t a t i o n of r e s u l t s a r e given. Included a r e s o m e clincial e x a m p l e s of d i f f e r e n t i a t i n g the s i g n a l of n o r m a l l i v e r and p r e g n a n t u t e r u s . (4 f i g u r e s , 9 r e f e r e n c e s ) ( U l t r a s o n i c s 1967, a b s t r a c t 675) 196
ULTRASONICS JULY 1967
No. 6, p. 148 (1967). Short d e s c r i p t i o n of an i m p r o v e d t u b e - d r a w i n g technique in which u l t r a s o n i c e n e r g y is applied to the fixed plug. It h a s been in o p e r a t i o n f o r a n u m b e r of y e a r s and can be u s e d on aluminium, i r o n - c o p p e r and n i c k e l - b a s e d alloys. Outside diam e t e r to wall t h i c k n e s s r a t i o s of 500 : 1 can be a c h i e v e d with b e t t e r f i n i s h e s . At l e a s t 10% r e d u c t i o n in drawing f o r c e i s obtained and the i n s t a l l a t i o n can be o p e r a t e d at h i g h e r s p e e d s and give l o n g e r tool life. No d e t e r i o r a t i o n in the m a t e r i a l p r o p e r t i e s h a s been o b s e r v e d . (3 f i g u r e s ) ( U l t r a s o n i c s 1967, a b s t r a c t 681)
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