New equlpm the analysis procedure.

Other new features of the software include subtraction of images, alignment of images and an extended plot function. All provide the user with greater flexibility when performing real time analysis of images on screen.

In addition to the 40 ° , 20 ° and 10 ° lenses already available with Thermovision 900, the company

is offering two new lenses enabling users to monitor the temperature of even smaller objects than before. The 5 ° and 2.5 ° lenses are both available for the thermoelectrically cooled shortware scanner and the liquid nitrogen or Stirling cooled Iongwave and shortwave scanners.

AGEMA Infrared Systems, Arden House, Leighton Buzzard, Bedfordshire, L U7 7DD, UK

On-site hardness testing Research to develop a new procedure for reliable on-site hardness testing of weld heat-affected zones (HAZs) in steel is starting at TWI. The project has been set up to help overcome problems with fabrication hydrogen cracking in steel weldrnents, and, in the long term, stress corrosion cracking.

Current portable hardness test equipment is not generally considered to be completely reliable for on-site hardness testing and often samples have to be removed for laboratory analysis. The project aims to

for steel weldments develop a reliable site testing procedure, produce guidelines for in situ weldment preparation and make recommendations regarding statistical significance.

The hardness profile of a weldment, its peak hardness and zone width, depends principally on two factors: plate chemical composition and weld cooling rate. As part of the project a range of carbon manganese steels, welding consumables and welding procedures will be selected to generate HAZs of differing characteristics. Comparisons will be made

A specialized portable testing machine being used to determine weld HAZ hardness levels

between hardness values determined using Vickers machines and Wells Krautkramer Microdur equipment.

The development of a successful procedure will increase confidence in the structural integrity of fabrications. It will maximize reliability of on-site measurements and help avoid fabrication cracking.

Companies interested in taking part in this project should contact Brian Ginn atTWI on +44 (0) 223 891162.

TWI, Abington Hall, Abington, Cambridge CB1 6AL, UK

Fibre optic measuring device A fibre optic measurement technique, developed by Cambridge Consultants, can maintain a level of accuracy better than 10 nm, in conditions previously too extreme for such technology. It has a wide range of potential applications, from pure research to industrial monitoring and microsurgery, where the device could be used, for example, to measure blood pressure during an operation.

The system is based on a new operating principle in which a passive sensing interferometer is linked by optical fibre to an active processing interferometer. Under these conditions the light propagates through the system in a mode that is immune to environmental perturbations such as temperature change, vibration and shock. By using this technique, external conditions that may affect the fibre no longer alter the measurement, as is the case with a number of alternative techniques.

The sensor head may be adapted to measure temperature, position, pressure, vibration or acceleration. Uses include the monitoring of machines that generate a high degree of electromagnetic noise, such as generators or turbines -

NDT& E International Volume 25 Number 1 1 992 51

-New equipment conditions in which it is difficult to use electrical sensors.

The sensor head can be made extremely compact and can be ruggedized against vibration. There is no risk of electrical sparks from the device and it can therefore be used in hazardous environments where volatile gases or vapours may be present. The use of temperature-resistant materials allows the device to be used in extreme conditions such as those found in jet engines or oil bore holes.

Cambridge Consultants Limited, Science Park, Milton Road, Cambridge, CB4 4DW, UK

On-line X-ray inspection system The conveyor X-ray system from Lixi is suitable for inspecting defects in products that move on a conveyor, must be 100% inspected without losing production time, are of larger size and that have defects that are not easy to distinguish from the surrounding areas. Many products fit some or all of the above criteria and are candidates for X-ray inspection with the system. Examples include food, medical devices, printed circuit boards, electronic components and small parts.

The first installation of the system is at a food plant which needed to ensure a fully boneless chicken product. The Lixi system is synchronized with the manufacturer's line speed, and as the packages enter the sealed and waterproof X-ray chamber, a real-time X-ray image is seen on the video monitor. The imaging is of high enough resolution that small bone fragments are clearly distinguishable. This is achieved through a particular setting of the power supply, and it can be changed for different products, depending on the material and the type of defects that need to be seen.

A feature of this application is

Conveyor X-ray system from Lixi for on-line inspection

that a large size product is inspected for defects that could be as small as 0.8 ram, and the inspection is performed at line speeds, rather than in a QC lab. This is achieved owing to the system's high dynamic range, up to 2000:1, and the small focal spot size of the X-ray generator (250 #m). Image enhancement technology also plays a role in providing clear pass-fail information on a video screen to the operator.

Lixi Inc, 1438 Brook Drive, Downers Grove, IL 60515, USA

Laser inspection The plastics, packaging and converting industries could save large sums through reduced scrap, better product grading and improved quality control if they installed automatic laser equipment to inspect sheet and film 15roducts, according to John Claridge, managing director of Image Automation.

Automatic laser inspection provides real-time defect analysis capable of pinpointing

J

problems in films or sheet. It can be applied to plastics extrusion and calendering processes as well as to blown-fi lm and cast-film production.

Automatic laser inspection produces a 'map' of a complete roll as it is being produced, allowing any defects to be assessed and action to be taken immediately, such as feedback to correct the process. Alternatively, defective sections can be removed from finished rolls or sub-standard rolls can be downgraded.

Information from the inspection can be readily incorporated into statistical process control systems and kept on file to satisfy BS5750/IS09000 procedures.

The company has just set up a dedicated evaluation facility at its London headquarters. Manufacturers are being invited, free-of-charge, to send product rolls for assessment. Image Automation wil l then provide a full report of any defects in the roll and invite the manufacturer to see the facility in action.

Image Automation Ltd, Kelvin House, Worsley Bridge Road, Sydenham, London SE26 5BX, UK

52 NDT&E International Volume 25 Number 1 1992