=--New equipment Replacement AE model has wider dynamic range

Improved signal fidelity and wider dynamic range are said to be two of the changes to the 1200A acoustic emission instrument from PAC which replaces the 1200 model.

A single-channel instrument, the 1200A detects in real time the magnitude of the energy release, amplifies and quantifies the signal and displays the signal's relative magnitude.

Priced at US $2595, the 1200A has a 101 dB dynamic range. The gain threshold levels and timing windows are adjustable, and audio and visual alarms can be preset to allow front panel control.

For more information contact: Sam Ternowchek, Director, Industrial Products, Physical Acoustics Corporation, Box 3135, Princeton, NJ 08540, USA

FFT analyser stores data for lab analysis

Remote control and storage of data is now possible with the AD3522 battery powered FFT analyser from Hakuto.

Data may be collected and stored in the field in the memory and then, when the user returns to the laboratory, put into any compatible computer system. The AD3522 has a built in CRT with video output so information can be displayed on monitors. The 1/3 octave frequency range has now been expanded to 16kHz to comply with the general requirements of the environmental, safety and testing fields.

For further details in Europe contact: Hakuto International (UK) Ltd, 33-35 Eleanor Cross Road, Waltham Cross, Herts EN8 7LF, UK

The AD3522 FFT analyser from Hakuto

Vibrometer can measure remotely A fibre optic laser vibrometer has been developed by Polytec for the routine analysis of vibration. It is a non-contact method which can make measurements at distances of several metres as well as differential and absolute measurements.

The system can analyse vibrations containing frequencies from DC to more than 1 MHz and the velocity range is 0.3 x lO -6 ms -1 to 10 ms -1. The dynamic range of measurement is more than 160 dB. The sensor heads are small and compact and are linked to the signal processor through optical fibres. The signal processing scheme is based on interferometric techniques.

range of applications to be covered. Not only single point but also differential measurements can be made with this system allowing background vibrational signals to be removed and torsional measurements to be analysed.

Laser Lines Ltd, Banbury, Oxon 0X16 7TQ UK

A range of sensor heads is available which can be connected to the fibres and enables a wide

Residual stresses measured magneto-elastically

Magneto-elastic measurement of residual stresses is the principle behind Stresscan equipment from American Stress Technologies Inc, which is being marketed in the UK by Ometron Ltd.

The continuous testing capability of Stresscan 100 allows for the monitoring of applied stresses varying with time; with chart recorder connected, a graph of these stresses can be obtained.

Various applications of Stresscan include static dynamic inspection of stresses in welded structures, bonded composite strips, steel mill rolls, gears, shafts, bolts as well as in stress relief annealing and other heat treatments.

Depth of measurement by the Stresscan 100 is 0.2 mm. More sophisticated is the Stresscan 500C, a programmable unit with 0.2 mm, 0.07 mm or 0.02 mm depths of measurement.

American Stress Technologies Inc, 515 Hollydale Drive, Bethel Parl~ PA 15102, USA or Ometron Ltd, Worsley Bridge Road, London SE26 5BX, UK

A linear current transducer developed for the determination of alternating currents in difficult locations or through large conductors has been introduced by Bonar Robinson of Cheadle, Cheshire, UIE The LCT 543 is being manufactured under licence from the Central Electricity Generating Board, who developed the system, and has applications wherever alternating currents need to be determined, whether as part of routine inspection or emergency maintenance procedures.

Based on the Rogowski coil technique, the transducer consists of a lightweight conditional amplifier and a measuring coil. This coil may be supplied in two forms, depending on the application. For situations where high levels of accuracy - O. 1 per cent - are required, or where the system forms part of a permanent installation, the LCT may be equipped with a rigid coil. However, should the conductor be particularly large or awkward in shape, a flexible, wrap-around coil is available, which can be tied around the conductor.

Bonar Robinson Ltd, Demmings Industrial Estate, Cheadle, Cheshire SK8 2PW, UK

250 NDT International August 1987