Thickness gauge

F o r use with aqueous o r o t h e r solvents, m o d e l s 125,250,500 and 1000 a r e v e r y s i m i l a r but differ in tank capacity, working f r e q u e n c y and mode of c o n s t r u c t i o n . The m o d e l s 250-2D and 500-2D a r e of the distillation type and f e a t u r e boiling solvent action and t w o - s t a g e tank a s s e m b l y . R e c o n d e n s a t i o n of the solvent vapour i s by w a t e r jacket witll r e g u l a t e d coolant flow.

m e t a l s production and fabrication; r e f i n e r i e s ; p e t r o l e u m and gas pipeline inspection, and shipbuilding and m a i n t e n a n c e . Nortec, 3001 George Washington Way, Richland, Washington 99352, USA

B r i e f d e t a i l s of the r a n g e a r e tabulated below. Sonor

125

250

500

1000

250-2D

Load

100W

250W

960W

1.68kW

1.25kW 2.96kW

Generating frequency in 100//s pulses

25kHz 25kHz 35kHz 35kHz

25 or 35kHz 45kHz

Capacity

1.11

3.41

3.41

8.01

18.01

500-2D

8.01

Haynes U l t r a s o n i c s , Queensway, Enfield, Middlesex, England DOUBLED BIT CAPACITY THICKNESS GAUGE

A p o r t a b l e u l t r a s o n i c gauge for m e a s u r i n g the t h i c k n e s s of m e t a l s and p l a s t i c s in a wide v a r i e t y of i n d u s t r i e s has been produced. Operating on the f i r s t back r e f l e c t i o n principle, the gauge (Fig 5) allows for m e a s u r e m e n t of rough and c o r r o d e d a r e a s on flat or c u r v e d s u r f a c e s . Developed by Nortec, the unit, model NDT-110, u s e s a duale l e m e n t , contact t r a n s d u c e r and t h i c k n e s s f r o m 0.05-2.00in can be r e a d d i r e c t l y on the c a l i b r a t e d m e t e r with a c l a i m e d a c c u r a c y of +1%. Specific u s e s quoted for the b a t t e r y operated, all s o l i d - s t a t e gauge include m e a s u r e m e n t of pipe wall and s t o r a g e - t a n k wall t h i c k n e s s , t h i c k n e s s of l a r g e r work p i e c e s w h e r e only one side is a c c e s s i b l e and plate t h i c k n e s s on ships. The NDT-110 can be e m p l o y e d in a i r c r a f t and a e r o s p a c e p r o d u c tion, m a i n t e n a n c e and overhaul; c h e m i c a l p r o c e s s i n g plants;

I m p r o v e m e n t s in f o r m i n g and finishing have r e s u l t e d in a h i g h e r m a x i m u m data r a t e of 16MHz and a new s t o r a g e c a p a c i t y of 4096 b i t s for the Cornlng G l a s s W o r k s ' high speed memory modules. C o r n i n g ' s Z e r o TC g l a s s , with its nominal t i m e - d e l a y t e m p e r a t u r e coefficient of z e r o , is the b a s i s of the i m p r o v e d module. Introduced e a r l i e r l a s t y e a r , the new m e m o r y module has l o w e r e d the p e r bit c o s t to 2 . 5 c e n t s for m e d i u m quantities and 1 . 6 c e n t s f o r quantities of 10 000 o r m o r e . With a s t a t e d delay t i m e of 64~s (128ps o r 256ps a r e a l s o specified) the module is suitable for e c o n o m i c a l c o m p u t e r display s y s t e m s w h e r e a t e l e v i s i o n s e t i s used as the h e a r t of the display. E l e c t r o n i c P r o d u c t s Division, C o m i n g G l a s s Works, C o m i n g , New York, USA E l e c t r o s i l Ltd, Pallion, Sunderland, County Durham, England

RESEARCH AND DEVELOPMENT MORE EFFICIENT CLAY DISPERSION

ACOUSTIC HYDROGEN DETECTOR

V a r i o u s s a m p l e s of clay have been i n v e s t i g a t e d to d e t e r m i n e the effect of e x p o s u r e to u l t r a s o n i c vibration.

Acoustic d e t e c t o r s have not been u s e d widely in gas a n a l y s i s b e c a u s e of the difficulty of identification of s p e c i f i c e l e m e n t s without s o m e p r i o r knowledge of the s a m p l e ' s c o m p o s i t i o n . However, a way of detecting at l e a s t one m o l e c u l a r s p e c i e s - hydrogen--has now been produced, b a s e d on the r e l a x a t i o n frequency of the e l e m e n t .

It has been found by Mihalik 1 that s h o r t - t e r m e x p o s u r e to u l t r a s o u n d does not affect the e l e m e n t a r y p a r t i c l e s of clay. However, d i s p e r s i o n i s quick c o m p a r e d to o t h e r methods of p r e p a r i n g s a m p l e s . B e t t e r breaking of soil a g g r e g a t e s , b e t t e r cleaning of the c o a r s e r p a r t i c l e s and m o r e efficient s e p a r a t i o n of the c o a r s e and fine p a r t i c l e s a r e obtained with the use of u l t r a s o n i c vibration. To provide a s t a n d a r d f o r use by o t h e r w o r k e r s , Mihalik r e c o m m e n d s that d i s p e r s i o n be p r o v i d e d by a m a g n e t o s t r i c tive t r a n s d u c e r with a frequency of 18-24kHz and an intensity of 3 W / c m 2 . E x p o s u r e to u l t r a s o n i c vibration should be 4rain, c o n c e n t r a t i o n of s u s p e n s i o n 5-10% and s a m p l e volume 100ml. Mihalik s u g g e s t s the use of sodium h e x a m e t a p h o s p h a t e (10ml, 0 . 5 n o r m a l ) as a d i s p e r s i o n agent. The use of u l t r a s o n i c vibration r e p r e s e n t s not only an i m p r o v e m e n t but also an a c c e l e r a t i o n and s i m p l i f i c a t i o n of the p r e p a r a t i o n of clay b e f o r e g r a i n a n a l y s i s and f u r t h e r m i n e r a logical a n a l y s i s . C a s o p i s , p r o m i n e r a l o g i i , r 13, ~ 2/1968. Publishing House of the C z e c h Academy of Sciences, Vodickova 40, P r a g u e , Czechoslovakia.

A diatomic molecule of hydrogen has s i x d e g r e e s of f r e e d o m , t h r e e i n t e r n a l and t h r e e e x t e r n a l . The new d e t e c t o r m a k e s use of the r e l a x a t i o n of t h e s e i n t e r n a l modes--one vibrational and two r o t a t i o n a l - - a f t e r a t h e r m o d y n a m i c d i s t u r b a n c e . If u l t r a s o n i c energy is applied to a s a m p l e n e a r the hydrogen r e l a x a t i o n frequency (that frequency at which the rotational component of the m o l e c u l e is changing with its m o s t r a p i d rate) c h a n g e s in the g a s e o u s sound velocity and s p e c i f i c heat capacity r a t i o will occur if hydrogen is p r e s e n t . T h e s e v a r i a tions a r e due to the reduction in the n u m b e r of d e g r e e s of f r e e d o m when the hydrogen molecule changes f r o m a diatomic to a m o n a t o m i c f o r m and the rotational energy c o m p o n e n t s a r e the e a s i e s t to m e a s u r e . The detection unit c o n s i s t s of a p a i r of u l t r a s o n i c t r a n s m i t t e r / r e c e i v e r s y s t e m s . One o p e r a t e s at a f r e q u e n c y above the r e l a x a t i o n frequency of hydrogen and the o t h e r at a l o w e r frequency. B e c a u s e the velocity of sound in the gas s a m p l e is a function ULTRASONICS J a n u a r y 1969

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