The Xiris Blog

Shutter Selection: Improve the Image Quality of Your Weld Camera

Posted by Cameron Serles on Thursday, October 02, 2014 @ 10:30 AM


Recent advances in electronics technology have made it possible for cameras with High Dynamic Range capability to be used to capture images of welding. This allow fabricators to be able to view the detail of the weld tip, as well as its immediate environment (such as the weld seam and weld pool) to get better control of the welding process. Reliable visualization of the environment around the weld tip is necessary to control and adjust the welding process. However, in order to be able to obtain the best possible image quality of a weld, the selection of the most suitable shutter technology must be made. The camera shutter type determines how and when light will be recorded during a camera exposure, and therefore determines the quality and functionality of the image that is provided. There are two main shutter types used in capturing images of welding: rolling or global.


Rolling Shutter

A rolling shutter captures an image by exposing one line at a time, moving from top to bottom. The rolling shutter capture technique is commonly used in film and can go largely unnoticed in certain applications. However, when applying this form of technology to the welding process, where high amounts of light with pulsing and movement are present, the image quality suffers. The image below demonstrates a rolling shutter exposure of a TIG welding process. As the picture demonstrates, some lines of the image get exposed during a welding pulse where a lot of light is present. These lines appear brighter than the rest. Other lines get exposed when the welding pulse is off when less light is present, these lines appear darker than the rest. Over time, if the pulse frequency does not match the frame rate of the camera, the line pattern will appear to move down the screen, causing a distracting image pattern to the viewer. In some cases, as material and surrounding background move past the rolling shutter, different images and movements would be captured, providing inconsistent results on which to base quality judgements of the weld.

Rolling_Shutter

 

 Effects of a Rolling Shutter on an Image of a TIG Weld Process


Global Shutter

A global shutter captures an image by exposing all rows of the sensor to light at the same time. This allows large amounts of motion to be captured at the same time, without blur or distortion. This type of shutter is also easier to pair with external applications such as external triggering or matching the image acquisition to a pulsed waveform of a welding power supply. When partnered with High Dynamic Range imaging capabilities, global shutter image capture is the most accurate and ideal technique for monitoring welding processes that involve motion or rapid changes in brightness. The drawback however, is that a global shutter image provides slightly lower contrast than a rolling shutter due to the fact that there is less time to expose each pixel, so in some situations, the image quality may not appear as vivid to the viewer as those taken with a rolling shutter.


CONCLUSION:

Advanced weld cameras such as the Xiris XVC-O partners both High Dynamic Range imaging capability with the choice of both rolling and global shutter capture modes to provide welding operators unprecedented image quality of their welding processes. By selecting the appropriate shutter technique, image quality can be optimized for the application.

 

To learn more about the Xiris XVC-O and other products,
please visit our website



 

Topics: weld camera, visibility

Decrease Injuries, Increase Efficiency and Prioritize Workplace Safety!

Posted by Leanne Sinclair on Tuesday, September 09, 2014 @ 05:28 PM

The construction of large ship vessels is a very complex and hazardous trade. In order to fabricate these large structures, there are various positions and maintenance that needs to be completed for proper assembly. Unfortunately, this increases the risk of accidents. As many shipyards use sub-arc welding, this process involves operators to be suspended high in the air, or exposed to different gases and hazards.

In 2011, two workers were fatally injured on the site of a Singapore shipyard, when a powerful explosion was caused due to the build-up of pressurized air. Fortunately, other team members were inside the nearby building attending a safety briefing when the accident occurred. The explosion shook the entire stretch near Benoi Road, and the loss of the two workers was mourned by various media outlets.  

Sadly, these types of accidents are common in this area of work. The article of this accident is accompanied with a chart that demonstrates that in 2007 14.3% of accidents occurring at shipyards were due to fire and explosions, most commonly associated with welding. The graph below demonstrates a study conducted by the Ministry of Manpower in 2013 of the Workplace Injuries by Industry and Degree of Injury. You will see that Construction, Manufacturing and Marine trades have the highest amount of fatalities and are the most common trades using welding.

table

 

These studies demonstrate the demand for increased safety in all of these trades, specifically shipbuilding. These huge constructions involve a variety of complex conditions and trades that need to be completed with efficiency and reliability. Risking a worker’s life by adding hazardous factors to an already dangerous trade is unnecessary and should be avoided. In order to complete reliable and quality welds, it is important that it is monitored, but this does not mean the operator must be where the weld occurs. With the development of welding cameras, injuries and fatalities in this industry can be largely reduced.

Systems such as the Xiris XVC-S Weld Camera for Sub Arc Welding can be added to conditions commonly seen in shipyards. This small addition could have large benefits, and large decreases in the high number of injuries and deaths seen in this prominent trade. It allows welds to be monitored consistently, from a safe distance, which would increase worker safety and efficiency.

 

Is your shipyard safe? Are your welds consistent and the best quality you can provide? Can you risk any more lost product, lost time, or employee safety?

To learn more about how Xiris Weld Cameras can benefit your business, please visit our website.

Topics: weld safety, weld environment, weld inspection, Sub Arc welding, weld camera, safety, accident, fatal, death, camera, visibility, weld allignment

Improve Safety for Submerged Arc Welding Applications!

Posted by Cameron Serles on Tuesday, August 27, 2013 @ 05:16 PM

Submerged arc welding processes are typically run as automatic or semi-automatic processes with automatic flux feed delivery systems. The automation of a sub arc welding process provides the fabricator with a number of distinctive advantages, such as higher quality, higher capacity, and of course much higher productivity in the fabrication process. 

Weld Cameras can improve monitoring of sub arc welding processes.

Automatic sub arc welding can be accomplished by moving the work piece underneath the weld head or moving the weld head over a stationary work piece. However, no matter how much of the process is automated, it is still important for the operator to have visibility of the welding process and see the parameters of the weld (such as wire feed speed, arc current and voltage, travel speed, and wire stick-out) to ensure that the weld process is running efficiently enough. 

If any parameter does go out of control, it is important for the operator to be able to see the process so as to make adjustments before the weld quality deteriorates.

Traditionally, the welding operator has had to be stationed near the weld head to be able to adequately see and manipulate the weld head. However, this close proximity to the weld head often puts the operator at risk and/or in extreme discomfort. This is due to commonly occurring conditions such as:

  • The operator has to sit high over ground to monitor a welded pressure vessel or assembly.
  • The operator has to work with restricted freedom of movement, which may include kneeling or sitting in a cramped space, such as inside a small diameter pressure vessel.
  • Conductive elements are present with which the welder may make accidental contact during the welding process, causing potential electrical shock.
  • The operator has to monitor the weld in wet, damp, or humid conditions, which reduce the skin resistance of the body and the insulating properties of accessories, causing additional potential of shock.

In all of these situations, health risks to the operator can be avoided by removing the operator from the immediate area of the weld environment. This can be accomplished using a Xiris XVC-S Sub Arc Camera. With the use of such a camera, the operator can monitor the progress of the sub arc weld from up to 40 meters away. 

The benefits of using the XVC-S? For the fabricator, easier compliance with an ever-increasing set of regulatory guidelines that limit how and when operators can access the weld area. For the operator, higher productivity by avoiding the distractions caused by the hazards of the immediate vicinity of the sub arc weld area.

Conclusion

Automatic or semi-automatic submerged arc welding requires in-process operator monitoring of the weld, which can best be achieved with a Weld Camera—freeing the operator from the health risks of direct proximity to the weld.

 

Image courtesy of ESAB.

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Topics: weld safety, weld camera, safety, Sub Arc welding, applications, visibility, weld

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