High frequency pulse generator

Panametrics have introduced the 5050M ultrasonic pulse generator designed to drive high frequency magnetostrictive transducers when measuring moduli and other physical pro- perties. Special features include simplified controls, a rectan- gular current pulse optimized for the Panaprobe 200 kHz magnetostrictive modulus transducer, adjustable pulse ampli- tude (O-500 mA, approximately 5 ps wide, 60 pps) and solid- state circuitry. The unit operates from 110 V, 60 Hz mains supply, is lightweight (0.8 kg) and measures 50 x 75 x 160 mm.

Panametrics Inc, 221 Crescent Street, Waltham, Massachusetts 02154. USA

Compact alarm system

J. J. Huber are now the UK distributors of the X-IC ultra- sonic alarm system (Fig.6) made by Spirig Ultrasonics of Switzerland. The X-IC is a compact (125 x 110 x 26 mm) lightweight (440 grm) protection system operating at 40 kHz with simultaneous am/fm detection of doppler frequency shift. It runs from 240 V ac or 12 V dc with automatic switching to an external 12 V dc NiCad accumu- lator in the event of mains failure. The accumulator is automatically recharged when the normal power supply is resumed.

Fig.6 The X-IC ultrasonic alarm

The sensitivity is adjustable from 300 mm to 9 m and an entire factory can be covered by a batch of the units monitored from a remote control panel. Any type of alarm can be triggered by the system which resets auto- matically after 30 seconds.

Spirig Ultrasonics, Rapperswihl, Switzerland

J. J. Huber Limited, Breakfield, Coulsdon, Surrey, UK

Miniature air transducers

MacDonald have developed two miniature piezoelectric ultrasonic air transducers - a transmitter, the UT40T and a receiver, the UT40R. Designed for general purpose opera- tion, both operate at 40 kHz and are designed to work over the temperature range - 15 to +65”C. The transducers have maximum external dimensions of 14 mm diameter x 18 mm long, including connecting pins.

MacDonald, 100 Clarendon Road, Ashford, Middlesex TW15 2QD, UK

Simplified materials research

Magnaflux have introduced a resonant frequency sonic test instrument for the precise measurement of material pro- perties. Designed to simplify applied materials research of both metals and non-metals, the Elastomat SR-200 (Fig.7) uses both piezoelectric or electromagnetic transducers with a frequency range of 600 Hz to 50 kHz. It provides data for dynamic modulus of elasticity, dynamic shear modulus, Poisson’s ratio and damping factor determinations. The oscillator frequency stability is within 0.01% and measure- ment can be made from very low temperatures up to 1 OlO’C with an optional high temperature furnace.

The control console includes a variable frequency oscillator, amplifiers, phase shifting network and semi-automatic con- trols. The numerical data readout is on an electronic counter module, and a frequency change per revolution of less than 0.2% is possible with the fine frequency control. The front panel includes a four position function selector, gain, phase, drive and motor controls. A meter indicates the relative amplitude of energy being transferred through the specimen material.

In operation, one transducer is connected to the variable frequency oscillator. This converts electrical energy into mechanical energy - vibrating the specimen. The other transducer converts the vibrations back into electrical signals. A rl count accuracy is possible. The counting time can be set at 0.01, 1 or 10 seconds, and the readout is 50 mm high, indicating total cycles or time of period. The unit has dimensions 457 x 495 x 457 mm and weighs 52 kg.

The manufacturers state that an important area of applica- tion for this instrument is in the study of variations in elastic and damping properties caused by metallurgical changes and changes caused by corrosion.

Magnaflux Corporation, 7 300 West Lawrence Avenue, Chicago, Illinois 6056, USA

Fig.7 The Elastomat SW200 sonic test instrument. Inset shows the optional electrical high temperature furnace for testing up to 1 olo”c

High resolution sonar diagnosis

Nuclear Enterprises have improved their Diasonograph NE 4102 sonar diagnostic equipment with the introduction of a new high resolution model (Fig.8). The all solid-state unit has two interchangeable display systems for the display of section-scan, A-scan or time/position scan.

206 ULTRASONICS, SEPTEMBER 1972

seals enables the instrument to be used both in the field and in the laboratory.

The unit, known as the BT-2 (Fig.9) generates low fre- quency ultrasonic pulses and measures the time taken for this energy to pass through the test piece, displaying the transit time on three numerical indicator tubes in micro- seconds. The controls have been kept to a minimum for simplicity. These consist of range control (O-99.9 or O-999 ps), zero adjustment and on/off switch. A battery state indicator is also provided. An accuracy of 0.1 ns is possible with the 10 MHz crystal oscillator, the percentage accuracy increasing with distance.

Terratest (Great Britain) Limited, St Thomas Road, Wigston, Leicester LE8 2TA, UK

Fig.8 The Diasonograph NE 4102 high resolution sonar diagnostic equipment in use at the Queen Mother Hospital, Glasgow, UK

These can be presented independently on either of the two systems. The upper display is a short persistence type while the lower is a variable persistence storage unit and carries an interface unit fitted with a caliper system. The lower unit also has a large scale illuminated digital readout which permits unobscured viewing of both displays and the digital readout while the caliper settings are being adjusted. This arrangement is standard, but as the display and interface units are interchangeable, the layout can be modified to suit individual requirements.

In the A-scan mode the display can be either full-screen or half-screen, with inversion facilities for photographic comparison of two successive echo patterns. The ranges are 5, 10,20,50, 100,200 and 500 mm in switched steps, and a O-500 mm continuously variable delay allows the operator to preselect the region to be examined.

A cross-sectional facility intensity modulates the com- pound scan pattern on an 8 x 10 mm display area and with it, the manufacturers claim, it is possible to visualize the gestate sac only a few weeks after conception. The scanned area is: horizontal 500 mm nominal; vertical 250 mm nominal. Probe rotation is possible through +lOO degrees from the vertical plane of scan.

In the time/position mode a continuously variable vertical sweep speed between x 0.5 and x 2 of 1,2.5, 10,25,50, 100 and 250 mm s-l, may be used to indicate the pattern of movement of soft tissue structures. The operating fre- quencies are 0.5, 1.5,2.5, 5 and 10 MHz. The transmitter prf is a fixed 300 pulses per second and a velocity con- trolled (section-scan only) 30-300 pulses per second. Colour coding and illumination of the controls ensure that the system is simple to use for non-specialist operators.

Nuclear Enterprises Limited, Sighthill, Edinburgh EHl 1 4EY, Scotland, UK

Portable materials tester

Terratest have announced an ultrasonic materials tester

for use on concrete, rocks, refractories, ceramics, grinding wheels, glass reinforced plastics and other materials. The instrument is lightweight, completely portable and operated from a rechargeable 12 V battery giving 10 hours continual use. A rugged case with water and dust resistant

Fig.9 The BT-2 materials tester

Catch that thief

Philips have introduced an ultrasonic burgular alarm for both home and industrial use. It will protect an area of about 15 m2 but with additional transducers this can be extended to about 35 m? The system is simple to use. To operate it the user pushes any combination of six but- tons on the instrument panel. They then have 30 seconds to leave the protected area before the system begins opera- tion. On returning, the user cancels the system by pres- sing the same combination of buttons. Additional alarms in the form of an extra loudspeaker, visual alarm or remote alarm can be added. The power supply is mains (220/240 V or 1 lo/l20 V) or 12 V dc external battery. The system weighs 1.85 kg with batteries and measures 80x268x 120mm.

Philips Electrical Limited, Century House, Shaftesbury Avenue, London WC2H 8AS, UK

Talking underwater

A self contained two-way ultrasonic communication system for divers has been developed by Helle Engineering Inc. The system, which comes in three models, turns on auto- matically when underwater and allows divers to talk to one another, with an underwater habitat or a ship.

The first model, the HE-10 (Fig.lO), is a two-way diver carried system and consists of a tank mounted electronics

ULTRASONICS. SEPTEMBER 1972 207