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On-line computer cuts analysis times
Equipment The equipment u s e d f o r the s u r v e y on the ' A t h e l l a i r d ' was the U l t r a s o n o s c o p e Mk 5. It i s t r a n s i s t o r i z e d , with b a t t e r i e s which l a s t about t h r e e working days at the n o r m a l r a t e of s e v e n h o u r s ' u s e a day. Acknowledgements This a r t i c l e is published by p e r m i s s i o n of the o w n e r s of the v e s s e l , Athel Line Ltd. The s u r v e y was c a r r i e d out by M a t e r i a l M e a s u r e m e n t s Ltd, 22 Station Road, Belmont, Sutton, S u r r e y , England, and we a r e indebted to M r Alan Brown of M a t e r i a l M e a s u r e m e n t s f o r his a s s i s t a n c e and c o operation.
out,)ut
HEAT PULSES DETERMINE THERMAL DIFFUSMTY OF VERY THIN SAMPLES The t h e r m a l diffusivity of a v e r y thin s a m p l e may be found rapidly and a c c u r a t e l y by o b s e r v i n g the t r a n s i t t i m e of a heat pulse f r o m a l a s e r through a p a r a l l e l - f a c e d s p e c i m e n . 1 The s h o r t d i s s i p a t i o n t i m e in the Q - s w i t c h e d mode (2 × 10-Ss) p e r m i t s m e a s u r e m e n t s of the t r a n s i t t i m e (Fig 23) as low as 5 x 10-he, without the c o r r e c t i o n s 2 n e c e s s a r y when t h e s e two t i m e s a r e s i m i l a r .
1
P a r k e r , W. J., et al, J o u r n a l of Applied P h y s i c s , Vol 32 (1961) p1679
2
L a r s o n , K. B., Koyama, K. J., J o u r n a l of Applied P h y s i c s , Vol 38 (1967) p465
R e a c t o r M a t e r i a l s L a b o r a t o r y , Culcheth, W a r r i n g t o n , L a n c a s h i r e , England (shown at The Physics Exhibition 1968)
T max
ON-LINE COMPUTER CUTS ANALYSIS TIMES O-SIT max-rc) A data analysis centre has been set up at the Institute of Sound and Vibration Research at Southampton University. Laboratories are connected to the system, which is based on a Marconi Myriad [[ computer, through coaxial cables. Electrical signals from microphones and other vibration transducers can be fed to the computer for rapid analysis, with results plotted in graphical form.
I
Loser
pu[se ~: occurs
r
t~
Tc
_,
- - - 5001~s.,
23
Signals are sampled 40,000 times per second and converted into binary code, using new analogue-to-digital converters. The system can be fed with signals from tape recordings if 'on-line' use is not required.
,~ Time
Power totoser
Oi-etectric mirror/
Furnace
i
~Jl.)lli.4 Ruby rod
~
1:7o,
~ - - - - - - d Specimen u . . . .
"ower .--'%,--~ ~1 ~ , r . . u o -4 ~S pp ,,
Thermo~peci,
,enJf
t-,-,llli'i.gU~/
/
l |
chamber J'" ,' , ." . "" ~~, ,,' ~"" ~ ' ~ \ J . . . . . . .mirror ~ Concave
I
network
I
I I Infra-red t or detec ,tector ~
Dr Colin Mercer, who is Lecturer in Structural Vibrations, is in control of the scheme. He is at present making some of the computer time available to outside organizations, particularly ear and aircraft manufacturers.
I
Bridge
'
I
17,~-;,;. I
L) }h trace "Lk~" tt-~ o Input
o.!_1 -e I ~ JA - - time
- I trigger C|B time 'o Ibase . • Storage trigger oscittoscope
24 S p e c i m e n s of a few thousandths of an inch have t r a n s i t t i m e s around 10-2s so t h e r m o c o u p l e s cannot be used: the t r a n s i e n t s a r e d e t e c t e d by an i n f r a - r e d d e t e c t o r (cooled by liquid nitrogen; r e s p o n s e t i m e l e s s than 2 x 10-6s) and an optical s y s t e m . With the equipment in F i g s 24 and 25, the v a r i a t i o n of the t h e r m a l diffusivity can be m e a s u r e d in the r a n g e 20-900°C. One application of the m e t h o d i s in the m e a s u r e m e n t of the v a r i a t i o n of the diffusivity of oxide f i l m s on s t a i n l e s s s t e e l b e f o r e and a f t e r i r r a d i a t i o n by n e u t r o n s and with r i s e of t e m p e r a t u r e . Also, a c o m p u t e r p r o g r a m m e has b e e n w r i t t e n to d e t e r m i n e the t h e r m a l diffusivity of one l a y e r of a t w o - l a y e r s p e c i m e n when the data for the s e c o n d l a y e r i s known.
WORLD'S FIRST INTERNAL ULTRA-VIOLET INSPECTION?
A w o r l d ' s f i r s t in n o n - d e s t r u c t i v e t e s t i n g i s c l a i m e d by Optec R e a c t o r s Ltd with the introduction of t h e i r UV L u m e x E n d o s c o p e . It is said to be the f i r s t e v e r s y s t e m that allows u l t r a - v i o l e t c r a c k d e t e c t i o n to be u s e d inside c a v i t i e s with e n t r a n c e a p e r t u r e s l e s s than 1/2in (12mm) in d i a m e t e r . The d e v i c e i n c o r p o r a t e s the s t a n d a r d L u m e x a i r - c o o l e d h a n d - h e l d lamp housing, which h a s been r e d e s i g n e d to take a c o m p a c t 200W m e r c u r y a r c lamp. A quartz rod light t r a n s m i s s i o n s y s t e m gives 160W of cold u l t r a - v i o l e t (switchable to white light) at the point of i n s p e c t i o n . T h i s is sufficient f o r endoscopic i n s p e c t i o n up to 20mm f r o m the endoscope; the optics give s h a r p focus down to 5mm f r o m the object glass. The u l t r a - v i o l e t endoscope (shown in F i g 26) can be o r d e r e d with i n t e g r a l dye and solvent a p p l i c a t o r feed. Application of dye and washing out a r e c a r r i e d out through the endoscope in n o r m a l white light, and then the s o u r c e i s switched to ultraviolet f o r f l u o r e s c e n c e examination. The h a n d - h e l d UV head can in addition be u s e d a s a p r o j e c t o r f o r naked eye i n s p e c tion in c a v i t i e s down to 25mm in d i a m e t e r . D i a m e t e r of the beam is 25ram, and it has a useful throw of at l e a s t 10m.
n o n - d e s t r u c t i v e testing May 1968
207
out,)ut
HEAT PULSES DETERMINE THERMAL DIFFUSMTY OF VERY THIN SAMPLES The t h e r m a l diffusivity of a v e r y thin s a m p l e may be found rapidly and a c c u r a t e l y by o b s e r v i n g the t r a n s i t t i m e of a heat pulse f r o m a l a s e r through a p a r a l l e l - f a c e d s p e c i m e n . 1 The s h o r t d i s s i p a t i o n t i m e in the Q - s w i t c h e d mode (2 × 10-Ss) p e r m i t s m e a s u r e m e n t s of the t r a n s i t t i m e (Fig 23) as low as 5 x 10-he, without the c o r r e c t i o n s 2 n e c e s s a r y when t h e s e two t i m e s a r e s i m i l a r .
1
P a r k e r , W. J., et al, J o u r n a l of Applied P h y s i c s , Vol 32 (1961) p1679
2
L a r s o n , K. B., Koyama, K. J., J o u r n a l of Applied P h y s i c s , Vol 38 (1967) p465
R e a c t o r M a t e r i a l s L a b o r a t o r y , Culcheth, W a r r i n g t o n , L a n c a s h i r e , England (shown at The Physics Exhibition 1968)
T max
ON-LINE COMPUTER CUTS ANALYSIS TIMES O-SIT max-rc) A data analysis centre has been set up at the Institute of Sound and Vibration Research at Southampton University. Laboratories are connected to the system, which is based on a Marconi Myriad [[ computer, through coaxial cables. Electrical signals from microphones and other vibration transducers can be fed to the computer for rapid analysis, with results plotted in graphical form.
I
Loser
pu[se ~: occurs
r
t~
Tc
_,
- - - 5001~s.,
23
Signals are sampled 40,000 times per second and converted into binary code, using new analogue-to-digital converters. The system can be fed with signals from tape recordings if 'on-line' use is not required.
,~ Time
Power totoser
Oi-etectric mirror/
Furnace
i
~Jl.)lli.4 Ruby rod
~
1:7o,
~ - - - - - - d Specimen u . . . .
"ower .--'%,--~ ~1 ~ , r . . u o -4 ~S pp ,,
Thermo~peci,
,enJf
t-,-,llli'i.gU~/
/
l |
chamber J'" ,' , ." . "" ~~, ,,' ~"" ~ ' ~ \ J . . . . . . .mirror ~ Concave
I
network
I
I I Infra-red t or detec ,tector ~
Dr Colin Mercer, who is Lecturer in Structural Vibrations, is in control of the scheme. He is at present making some of the computer time available to outside organizations, particularly ear and aircraft manufacturers.
I
Bridge
'
I
17,~-;,;. I
L) }h trace "Lk~" tt-~ o Input
o.!_1 -e I ~ JA - - time
- I trigger C|B time 'o Ibase . • Storage trigger oscittoscope
24 S p e c i m e n s of a few thousandths of an inch have t r a n s i t t i m e s around 10-2s so t h e r m o c o u p l e s cannot be used: the t r a n s i e n t s a r e d e t e c t e d by an i n f r a - r e d d e t e c t o r (cooled by liquid nitrogen; r e s p o n s e t i m e l e s s than 2 x 10-6s) and an optical s y s t e m . With the equipment in F i g s 24 and 25, the v a r i a t i o n of the t h e r m a l diffusivity can be m e a s u r e d in the r a n g e 20-900°C. One application of the m e t h o d i s in the m e a s u r e m e n t of the v a r i a t i o n of the diffusivity of oxide f i l m s on s t a i n l e s s s t e e l b e f o r e and a f t e r i r r a d i a t i o n by n e u t r o n s and with r i s e of t e m p e r a t u r e . Also, a c o m p u t e r p r o g r a m m e has b e e n w r i t t e n to d e t e r m i n e the t h e r m a l diffusivity of one l a y e r of a t w o - l a y e r s p e c i m e n when the data for the s e c o n d l a y e r i s known.
WORLD'S FIRST INTERNAL ULTRA-VIOLET INSPECTION?
A w o r l d ' s f i r s t in n o n - d e s t r u c t i v e t e s t i n g i s c l a i m e d by Optec R e a c t o r s Ltd with the introduction of t h e i r UV L u m e x E n d o s c o p e . It is said to be the f i r s t e v e r s y s t e m that allows u l t r a - v i o l e t c r a c k d e t e c t i o n to be u s e d inside c a v i t i e s with e n t r a n c e a p e r t u r e s l e s s than 1/2in (12mm) in d i a m e t e r . The d e v i c e i n c o r p o r a t e s the s t a n d a r d L u m e x a i r - c o o l e d h a n d - h e l d lamp housing, which h a s been r e d e s i g n e d to take a c o m p a c t 200W m e r c u r y a r c lamp. A quartz rod light t r a n s m i s s i o n s y s t e m gives 160W of cold u l t r a - v i o l e t (switchable to white light) at the point of i n s p e c t i o n . T h i s is sufficient f o r endoscopic i n s p e c t i o n up to 20mm f r o m the endoscope; the optics give s h a r p focus down to 5mm f r o m the object glass. The u l t r a - v i o l e t endoscope (shown in F i g 26) can be o r d e r e d with i n t e g r a l dye and solvent a p p l i c a t o r feed. Application of dye and washing out a r e c a r r i e d out through the endoscope in n o r m a l white light, and then the s o u r c e i s switched to ultraviolet f o r f l u o r e s c e n c e examination. The h a n d - h e l d UV head can in addition be u s e d a s a p r o j e c t o r f o r naked eye i n s p e c tion in c a v i t i e s down to 25mm in d i a m e t e r . D i a m e t e r of the beam is 25ram, and it has a useful throw of at l e a s t 10m.
n o n - d e s t r u c t i v e testing May 1968
207