Equipment review

EQUIPMENT REVIEW CO-OPERATION

IN

NON-DESTRUCTIVE

Washing buses

TESTING

Two working parties appointed by the British National Committee for NonDestructive Testing are trying to organize co-operation in research into non-destructive testing. The first working party has already reported in a paper by A. Nemet just before the second party was set up in November, 1963, under Dr. Nemet's chairmanship. The first party chose power generation, aircraft and steel as typical industries and was able to find a number of c o m m o n problems in apparently unrelated industries. The present party is compiling a list of problems which includes items like ultrasonic attenuation in solids and the examination of adhesive bonds. It hopes to find out who is doing research and where research is lacking and would like to hear from universities, industry, government laboratories and research associations who now have work in progress or about to begin. By its nature the working party can only co-ordinate and make recommendations but it is clear that co-ordination is badly needed. Correspondence should be sent to the Secretary of the Committee at The Institution of Mechanical Engineers, 1 Birdcage Walk, London, S.W.1. Dr. Nemet's paper appeared in The Engineer on 23 February, 1963.

Ultrasonolux The instrument devised by W. Buschmann to examine defects of the retina is a combination of an ordinary ophthalmoscope and a barium titanate transducer. The transducer is mounted at the end of a rod of damping material, finely divided tungsten in Araldite, and both are embedded in a Perspex block housed in a metal case. The ends of the case are open revealing the curved surfaces of the Perspex. Light from a conventional ophthalmoscope is directed at the larger end of the Perspex, which is convex, and passes through the block and out at the smaller end. The small end is concave in a radius of 8 mm and coupled to the patient's eye with Methocel. At the same time pulsed 10 Mc/s ultrasound is

The Ultrasonolux consists of a Perspex block with a transducer embedded in it, the whole surrounded by a metal case

emitted from the transducer and the reflected pulses received on the same transducer. While one operator looks at the retina through the Ultrasonolux a second operator watches the A-scan for echoes. Lesions are first found optically and then their position is made precise by maximizing the echo on the A-scan. Lesions of the retina are usually measured in diameters of the optic disc. The transducer is less than 1 diameter across and lesions of only 2 diameters can be accurately pinpointed. The Ultrasonolux can also be used to display lesions of the arteries, particularly the carotids where they run close to the skin. Arteries down to 1.5 rnm bore can be examined.

Buses can be washed at more than one a minute in this automatic washing plant controlled by ultrasonic sensors. Westool Ltd.

Automatic control of a 40 sec washing cycle by ultrasonic sensors means that 60 buses can be washed in one garage each night. A pair of Sonac focalizer sensors is mounted 7 ft from the ground on either side of the entrance to the washing plant. When the bus is driven between them the beam is broken and for 40 sec a total of 42 jets of water, aided by nylon brushes, scrub the bus clean. Then an auto-timer switches the water off and the bus is driven out of the bay. The sensing heads are hermetically sealed in steel cylinders and the control unit is contained in a weatherproof box on the mounting of one of the sensors.

Westool Ltd., Bishop Auckland, County Durham, England. Modular sensor Amplifiers for the range of sensing equipment made by Westool Ltd. can now be rapidly interchanged. All the different types of amplifier, for different voltages and different control functions, now plug into a c o m m o n type of base which contains all the connections between the amplifier, the sensors and the source of power. Transistor circuits are used in the amplifier. Each control unit now has a pilot light and can have a built-in counter if necessary. Apart from the obvious advantage of quick interchange of amplifiers it is now easier to trace faults in the system. Our picture shows the base amplifier and outer casing surrounded by a selection of sensors. Westool Ltd., Bishop Auck-

land, County Durham, England. Plastics welder Plastics that are in the form of sheets such as Melanex and polythene can be joined together by applying a vibrating tool to two overlapping layers. Rigid plastics need a different technique. The

Modular amplifier for Sonac consists of amplifier and base enclosed in a heavy protective case

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ULTRASONiCS~January-March 1965

45

Type 1133 Sonic welder with a range of detachable heads. Timer and generator on the left. Dawe Instruments Ltd.

1133 Sonicwelder which is now being built under licence in the U.K. by Dawe Instruments Ltd. can be used for either kind of plastic. When two rigid parts of a plastics such as polystyrene are to be welded, the tip of the vibrating tool is simply applied to one member under a steady static pressure which can be adjusted to suit the component. Time of application is also adjustable; it can be as little as one second. The heat generated at the interface of the two parts melts them at the interface only and the static pressure forces them together to produce a perfect seal. The walls of the components can be between 30 mil and 250 mil thick. If the components are too large to be welded over their whole area by one application, the transducer tip can be applied to several different points in succession. The illustration shows the solid state generator and time setting circuits alongside the sealer, which is fitted with one of its detachable heads. Dawe Instruments

60W welder being used to weld fine gold wires to gold plated glass. M.E.L. Equipment Co.

Transducers are available at 20 kc/s or 30 kc/s with inputs from the mains of 150W or 500 W. The lower power models are air-cooled. Transformers for longitudinal wave or shear wave applications can be supplied. Uses are sealing of plastics or the dispersion of liquids in spray drying or cooling. Omega Laboratories Ltd., 57 Union Street, London,

S.E.1. Machining Three versions of the Sonorode ultrasonic drill by Kerry's (Ultrasonics) Ltd., 100 W, 50 W and 25 W, can all be driven from the standard generator. Magnetostrictive transducers are cooled by forced air. Recirculating slurry pump and work table can also be fitted. Holes from 0.02 in to 1.25 in diameter can be drilled. Greatest depth is 0.75 in on the standard equipment. Kerry's (Ultrasonics) Ltd., Warton Road, London, E.15.

Ltd., Western Avenue, London, I4:.3. Welding gold wires A 60W ultrasonic welder is being used by Mullard to weld 0.003 in gold wires to a gold-plated glass substrate. The substrate and its gold-plating are miniature circuits being evaluated by the Thin Film Division and the wires are the connecting leads. Because the weld area is small, the join must be made with virtually no heating, which is possible by ultrasonic means. So far the welds have been found stronger than the parent metal. M.E.L. Equipment Co. Ltd.,

I

Kerry's 100 W Sonorode with slurry pump and work table. Detachable velocity transformers on right

Continuous inspection of pipe Pipe up to ~ in outside diameter can be inspected continuously by the Model 76 inspection system shown here. The system includes mechanisms for feeding the pipe, tubing or bar continuously under the transducers which are coupled through water to the workpiece. A variety of transducers is made to detect flaws with different orientations: scanning can be between 0 and 200ft of surface per minute; the pitch of the helical scan can vary between 0 and 180 °. De-aerated water eliminates bubbles and false signals and can be supplied at up to 17 gal every eight hours; alarm and marker units can be fitted. Most systems are specially built to the customer's needs. TAC Technical Instrument Cor-

poration, Mercer County Airport, Scotch Road, Trenton, N.J., U.S.A.

Manor Royal, Crawley, Sussex, England. Magnetostrictive transducers Four different types of magnetostrictive transducer make up the Series 500 now available from Omega Laboratories.

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Autosonies for Czechoslovakia 500 W magnetostrictivetransducer from Omega Laboratories

ULTRASO~CS/January-March 1965

A second system, similar to the one we described in January, 1963, is being

Sensing heads and control console of Autosonics automatic tester for bars and billets supplied to Czechoslovakia by S. Smith & Sons. The system provides for automatic and continuous inspection of bar and billet stock. S. Smith & Sons,

Wembley Park Drive, Wembley, Middlesex, England.

holds 30 gal. Filters are not necessary as the debris consists of pieces of rubber seldom smaller than ~ in. Dawe Instru-

ments Ltd., 14/.3.

Western Avenue, London,

Cleaning rubber moulds The 3-bath cleaner shown here was built by Dawe Instruments to clean the moulds used in manufacturing small articles of vulcanized rubber. The moulds are of metal and their crevices become coated with a carbon film to which small pieces of rubber adhere. The debris can only be removed by ultrasonic cleaning. The moulds are first immersed in the right-hand bath, which contains six submersible transducers and a heater, are then transferred to the heated centre bath and finally to the lefthand bath for a spray rinse. Each bath

Model 76 continuous inspection plant for tube and bar. PAC Technical Instrument Corporation

5½ gal 4-stage automatic cleaner by L. & R. Ultrasonics Ltd.

577 Elm Street, Kearny, N.J., U.S.A.; L & R Ultrasonics Ltd., 20 Northburgh Street, London, E.C. 1.

Cleaning street lights Three-bath ultrasonic cleaner for cleaning vulcanized rubber moulds. Dawe Instruments

4-stage automatic cleaner We show here the largest of the range of cleaners from L & R Ultrasonics Ltd., similar in operation to the jewellery cleaner described on page 103 of the April-June, 1964, issue: this machine holds 5½ gal. 5 0 0 W of power are supplied from a separate generator to the cleaning and rinsing stages. Components to be cleaned are contained in a detachable metal basket which is lowered successively into the four processing positions. The usual combination is one cleaning, two rinsing and one drying stage. Once the machine has been started it carries out a complete cycle without supervision. Loading is merely a matter of unclipping the basket and replacing it by one full of dirty components. Generators are cooled by air draught and in the drying position the components have warm air blown over them. Cycling times can be pre-set at will. L & R Manufacturing Ltd.,

To clean the small crevices and large areas of glass of a street light globe Powertron Division of Giannini Controis Corporation have developed a truck-mounted cleaner. At least four large cities in the U.S.A. are using the units regularly. The contractor removes the globe and lowers it into the truck below him where it is placed in a special

2-1 kW generator and 32 gal sealed tank showing globe in position in cradle. Powertron

ULTRASONICS[1anua~.-March 1965

47

Wire delay line A new range of wire delay lines has been announced by M.E.L. Equipment Co. Ltd. Each line consists of a magnetostrictive wire as the delay, together with solid state input and output circuits. Different lines have delays ranging from 100bts to 3-2 ms and are each adjustable over a range of 20/zs. Up to 1,000 bits can be stored. Bit rates can be up to 350 kc/s. The delay lines will operate from - I O ° C to + 6 0 ° C and need only a 12 V Soniclean 1191B self-tuning generator being used with a 5 gal tank to clean ball bearings. Dawe Instruments Ltd.

cradle above a 32-gal cleaning tank. Closing the lid of the tank lowers the cradle into the cleaning liquid which is then agitated by 28 kc/s ultrasound. Power for transducers is supplied by three 700 W generators in a separate air-cooled cabinet mounted on the truck. The only controls are a temperature setting, an on/off switch and a timing knob. Powertron's representatives are: Philips Export Company, 100 East 42nd

the standard from an internal quartz crystal and displays the reading. The process takes 4 seconds. The gauge is rugged and portable and runs from a rechargeable battery. Battery output is stabilized. Westland Aircraft Ltd., Strain

Gauge Department, East Cowes, Isle of Wight, England.

Wire delay line and input and output circuits by M.E.L. Equipment Co. Ltd.

Street, New York, U.S.A. power supply. They are suitable for most transistor logic systems. Information is retained in the line as long as the power supply is kept on and may be extracted with a maximum access time equal to the total delay. Each line is mounted in a plated steel case approximately 9 in x 6 in x l in. F o r use when the line is mounted in a rack, one of the narrow sides carries a front panel with delay control and output test point. Power and signal inputs and outputs are then at the rear. M.E.L. Equipment Co. Ltd., 207 King's

Self-tuning generator F o r use with medium-sized cleaning tanks, about 5 gal is the suggested capacity, Dawe Instruments have introduced a self-tuning generator called the Type l l 9 1 B Soniclean automatic. It consists of a transistor oscillator transformer-coupled to a push-pull output stage which is in turn transformercoupled to the transducers. Feedback from the transducers adjusts the input of the amplifier and matches the frequency of the output to the resonant frequency of the transducers, which changes with temperature, cleaning liquid and the amount of liquid in the tank. The power input of the transducers is about 300 W average; main input is 600W. Output from the generator is at about 25 kc/s modulated at 100 pulses per second, twice mains frequency. The only controls are an on/off switch and a pilot light. Dawe

Instruments Ltd., Western Avenue, London, W.3. Strain gauge comparator F r o m the need to monitor sonic strain gauges embedded in reactor pressure vessels, Westland Aircraft Company have evolved a portable strain gauge comparator which presents sonic vibration frequency as a four-digit readout. The comparator automatically plucks the gauge, compares its frequency with

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ULTRASONICS~January-March

Cross Road, London, W. C.1.

Portable strain gauge comparator by Westland Aircraft Ltd.

Compact automatic cleaner Series D cleaner from Branson Instruments Inc. uses all solid state circuits and incorporates a heater and automatic tuning. The tank is of stainless steel approximately 5 in x 5 in x 6 in; cooling fins replace the more usual cooling fan so that the circuits can be completely enclosed. There is a thermostatic cut-off to prevent overheating; power output is 50 W average. Branson Instruments Inc., 37 Brown House Road, Stamford, Con-

necticut, U.S.A.

1965

Sonogen D50 automatic cleaner from Branson Instruments Inc.