New Weld Viewing Systems<br>from Oxford Lasers

Proprietary diode laser technology combined with cameras has resulted in VisiWeld – imaging systems of unprecedented capability. VisiWeld can see and record close-up images of the weld process where the field of view can be as small as 10mm x 10mm, it can capture transient effects or events that may last as little as 1ms, it allows users to work in complete safety by watching a monitor screen instead of trying to look directly into the fireball, and it is so compact that the air cooled system can be used in the field as well as in the laboratory. Weld fireballs generally saturate part of any captured image leaving other parts in darkness. Even if very powerful extra lighting is used, it is very difficult to see anything other than the fireball itself. VisiWeld systems combine two techniques to eliminate light from the arc and capture images with amazing clarity. First the fireball is illuminated using a laser and the camera is fitted with a filter that only allows laser light to penetrate. This means that most of the light from the fireball or 2/ ….. High Performance Weld Viewing Systems from Oxford Lasers weld process (which emits a broad range of wavelengths) is blocked and can be reduced by a factor or 100 or more. Secondly the lasers can be configured to deliver short pulses of light, while the fireball emits light continuously. If the camera is fitted with a very fast shutter that is only open during the laser pulse, the light from the fireball can again be minimised without reducing the amount of laser light. This can reduce the light from the fireball by a further factor of 100 or more. Combining these two techniques can reduce the effective brightness of the fireball by a factor of over 10,000 so that welding processes can be imaged with extreme clarity and without motion blur. These images can then be studied while the weld process is going on or stored and used for detailed study and research later. VisiWeld advanced weld viewing systems use integrated lasers for illumination and are available for general purpose weld viewing with good quality images at standard frame rates, or for time resolved studies and research a high performance system is available using a 5 kHz pulsed laser and high frame rate camera. Optional accessories are offered to expand the range of information that can be gathered, such as data logger system; extended working distance lenses; particle size and velocity measurement software; flow field velocity measurement software and /or hardware; and high magnification /short working distance lenses.