NEW EQUIPMENT

DRILLING AND MILLING OF CERAMICS

Two ro ta ry uRrasonic machines for working ceramic and glass components, as well as metal, have now been made commerc ia l ly available after severa l years of operational work with the prototypes. Ar i s - ing from an original idea at AERE Harwell, Sonimill and Sonidrill have been finally developed with addi- tional facil i t ies by McLean Research, Sonidrill being designed for smal ler scale machining.

The sys tems are based on a 150 watt Sonorode t rans - ducer f rom Kerry Ultrasonics Ltd, into which is fitted a diamond abrasive cutting tool of an appro- priate shape. Combined ro ta ry and ul trasonic (nomi- nal frequency 20kHz) vibrations, provide the required cutting action. The downward feed of the head is controlled by a sensitive hydraulic system applied to a counterweight, the head being self-returning. Maximum heights of workpieces which can be accom- modated are about 410mm and 220mm for Sonimill and Sonidrill respectively.

McLean Research Engineering Co Ltd, Hungerford, Berks, UK

change, eliminating false a la rms due to swaying cur - tains etc.

This system, the Systron Donner UD-6, incorporates all the advantages of ultrasonic sensing, such as pre- cise confinement of the protected area and failsafe design.

Systron Donner Ltd, St Mary ' s Rd, Sydenham Industrial Estate, Leamington Spa, Warwickshire, UK

ULTRASONIC TESTER FOR CONCRETE

A new 'Por table Ultrasonic Non-destructive Digital Indicating Tes te r ' , known as PUNDIT (Fig 2), is announced, for use on site to indicate variat ions in quality of concrete and cement. The two t ransducers for this through- t ransmiss ion instrument use high sensitivity lead zirconate titanate ce ramics at an operating frequency near 50kHz. Accuracy is to 1/2 or 1 microsecond (switchable) for material of thickness between 0.1 and 10 metres .

C. N. S. Instruments Ltd, 61-63 Holmes Rd, London NW5, UK

BURGLAR ALARM FOR UK MARKET

A new ultrasonic intrusion-sensing device (Fig 1) is now immediately available in the UK. Based on the established principle of detecting certain movements by their Doppler effect, an area up to 800m 2 (7,500ft 2) is filled with sound energy at 19.2kHz by mounting t ransmit t ing ' twee te rs ' in the protected area. Re- ceiving tweeters detect the 19.2kHz signal returning, and should it be shifted by the Doppler effect by an amount near 40 cycles, an a larm condition is caused. Movements other than human tend to set up f re - quency-changes of a different order to the 40-cycle

Fig 1 Burglar a larm unit with cover and t r a n s m i t / r ece ive t r~n~lucer pair ( ' tweeter')

Fig 2 Portable ttltrasonic t e s ter in operation on a concrete sample

MODULAR ULTRASONIC TESTER

A new British flaw detector (Fig 3) is announced by Ultrasonoscope, with applications in both the indus- tr ial and medical fields. Known as the Series 10 modular equipment, it consists of three main plug-in units: the amplifier module, the t ime-base module and the a larm module. These provide standard frequency

ULTRASONICS April 1971 71