The Xiris Blog

Welding is not a very colorful operation. The metal, torch and other materials are usually varying shades of grey. The arc is bright white. The background is almost black. To accurately monitor and inspect welds, being able to see a massive tonal range, from the brightest to the darkest, is essential.

 Color and Monochrome images of a TIG Welding Proces

Standard cameras, and even the human eye, are incapable of distinguishing all features when faced with such a range of brightness. However, Xiris’ high dynamic range weld cameras can, either in color (the 1100 and 1100e) or black and white (the 1000 and 1000e).
As humans, we often think that color is better. But in weld cameras, that is not always the case. Determining whether a color or monochrome weld camera will work best depends on a company’s operations. Here are five questions to consider when choosing between color and monochrome weld camera:

1. What kind of welding process are you using?
TIG (GTAW) or Plasma welding benefit most from being viewed in color, simply because there is more color present in those welding processes. Evaluating the color of the torch tip, shielding gas, melt pool and even the Heat Affected Zone can help operators to assess the quality of the weld.

2. What do you want to monitor during welding?
For example, do you want to see certain features, such as the boundary between the end of the torch and the shielding gas and arc? That might help you closely monitor the integrity of the torch tip and avoid contamination.

Or, are you concerned about the amount or type of shielding gas in the process? The shielding gas can sometimes take on a unique color as it is consumed by the welding arc. Changes in the color can signify a change in the gas chemistry and alert operators to the possibility of impurities.

Or is the Heat Affected Zone (HAZ) of interest? The leading edge of the HAZ may become visible as the parent material colorizes at elevated temperatures. This can indicate the amount of heat penetration and energy transfer made during the welding process. Discoloration of the metal can signify the presence of excess heat.

3. Is color more important than resolution?
To generate a color image, the image sensor in the weld camera is “painted” with color filters. Each pixel becomes filtered with red, green or blue light in a standard pattern known as a Bayer pattern. The imaging software then mathematically recombines the pixels into a color image. One drawback of this process is that the resolution of a color image is decreased by approximately half compared to that of a monochrome image.

With higher resolution, monochrome cameras generate images with sharper detail than color cameras. In monochrome images, edges appear crisper and subtle details are more visible—important for assessing the texture of the melt pool, for example. However, the hues in a color image give the human eye the ability to better evaluate boundaries between various weld components, like the melt pool, torch tip and shielding gas.

4. Is camera speed important for your operation?
Despite being lower resolution, color image files are larger than monochrome because each pixel is described by 3 bytes of data, whereas in monochrome images, only 1 byte of data is required. As a result, a color camera often will transmit data slightly slower than a monochrome camera to its output device.

5. Does color provide additional information that can help your welding process?
Everyone’s welding operation is unique. You may have additional features such as guiding markers on your parent material, or wire being fed into the welding process that might be best suited to monochrome or color cameras. Our team can help you to assess your needs and advise whether color or monochrome will work best for your application.

Whatever the operational needs, Xiris’ weld cameras, in either monochrome or color, provide high contrast, clear images of the welding process, allowing manufacturers to quickly and easily monitor their welds for better process control.

Who doesn’t love an inspiring transformation story? Weld inspection systems truly are capable of transforming your quality assurance processes and one of our Spanish customers has quite the story to prove it.

Tubos de Legutiano Automoción (TLA) is a manufacturer of high-quality tubular products for the automotive market. By producing thin-walled exhaust pipes, TLA helps their customers reduce the weight of their parts, while maintaining high quality standards that are able to withstand the strict demands of the automotive industry.

TLA recently said that their most important customer, a large automotive parts supplier based in France, was both surprised and delighted to notice a sudden, significant improvement in TLA’s quality, so much so that they wanted to pay them a visit.

Once visiting TLA, the French automotive parts supplier realized that the improvement in quality was due to the introduction and implementation of the Xiris WI2000 Weld Inspection system used on their two tube lines.  By detecting defects that were previously not detectable using any other NDT test process, TLA was able to address the imperfections that were plaguing their production for years.

The management of TLA commended Xiris’ systems saying:

“Without precision tools that allow us to move forward and work under this precept, it would be difficult to be able to develop products according to the new demands. That is why the Xiris WI2000 has been the key for increasing the quality of our company, reducing set-up times, monitoring the quality of the product in real time and allowing to interact with accurate information in the production process.”

The result was that, once implemented, the WI2000 systems were able to catch defects and help perform better process monitoring to keep their tube product in control.  Consequently, fewer defects made their way to the end of the production line and shipped to their customer in France.

During tube production, immediately after the tube has been welded and before any further in-line processing is done, the weld bead must be scarfed off the tube. Scarfing is the process whereby the weld bead is cut off with a knife, or scarfing tool.  Unfortunately, if the scarfing tool is not done properly, the tube may not meet end user customer specifications because of a rough surface left behind by the scarf tool.  The result can be the primary contributor to creating a leak path on a compression fitting.

Using a surface profiling tool such as the Xiris WI2000, the scarf defect measurement can be used to detect how well the scarfing tool is cutting the weld bead and indicate the amount of scarf tool wear. 

Scarf tool wear describes the gradual failure condition of a scarf cutting tool on a tube mill as a result of ongoing use.  It can occur either as flank wear in which the portion of the scarf tool in contact with the welded tube erodes over time sometimes causing a ridge to be left behind in the scarf zone; or as crater wear, in which contact with chips of weld bead erodes the rake face of the tool causing an uneven cut surface; or a cluster of weld bead material building up on the face of the tool causing it to dredge a groove in the scarf zone. These conditions are somewhat normal for tool wear, and they do not seriously degrade the use of the scarf tool until it becomes serious enough to cause a scarf tool cutting edge failure that may be a concern for a potential leak path for the tube in its final use.

The scarf defect measurement on the WI2000 looks for any significant deviations in surface height above or below the ideal scarf surface.  The Scarf Defect will detect the absolute value of the largest defect on the scarf surface.  Any significant amount of scarf tool wear could reduce the specifications and performance of the final tube, especially for some automotive applications where tight assembly requirements or a smooth, scratch free surface is required.

The Definition of a Scarf Tool Wear: The scarf plane can be defined as the straight line drawn between the left and right scarf edges.  Any detected features above or below the scarf plane, are measured as a scarf defect.  The actual amount of wear is defined as the distance from the scarf plane measured perpendicularly to the scarf plane.

If you have any questions about our profile inspections for tube and pipe, please feel free to contact us. 

Xiris' WeldInspection System Helps Identify the Root Cause of Variations in Tube Production

Many applications require tube producers to identify and document their tubes by batch, date and sometimes even time stamp for trace-ability. If a tube segment fails at a sub process or worse at the end user, a detailed analysis and root cause investigation follows.

Audit Log Files from Xiris' WeldInspection System

When the original tube production date and time information is available, a helpful tool to identify anomalies is to review the audit log files generated on Xiris’ WeldInspection system.The audit log files are date and time stamped and easily accessible to look for any weld related geometries that may have deviated for a time period during the production run.

Variations may be a change in bead shape/size that can be an indicator of squeeze pressure or weld heat change. With the WeldInspection system monitoring multiple geometrical conditions such as mismatch, bead height, width and potential freeze line, much information can be gained by reviewing the log files and identifying a potential root cause. Additionally if a particular condition has been identified as the potential cause, the audit logs can be utilized to determine for how long that condition existed therefore helping reduce the volume of product that might be quarantined for further evaluation.

If you are interested in learning more about how our WeldInspection system can benefit you and your company, please contact us here.