Modern Metals - Advanced Gauging Technologies

Article by Emily Vasquez and appears in Modern Metals Magazine, September 2015.

Service center realizes unexpected savings by upgrading gauging system

September 2015 – Where there is a problem, there must be a solution. When Vince Gallo first arrived at Nova Steel in 2013, he noticed the Stoney Creek, Ontario, facility was using an older gauging device that needed to be replaced with something far more accurate. The pickling line at the service center had an X-ray gauging system in place, but it was “difficult to read and effectively distribute gauge charts,” says Gallo. “People today want more accurate, precise information.” Seeking to increase its capabilities, Nova Steel installed a new slitting line along with new state-of-the-art measuring technology, improving process control and increasing output.

“We had some old gauging devices installed on our pickling line,” says Gallo. In September, we ordered a new slitter but, as we had very limited gauge reading capabilities, we called on Advanced Gauging Technologies again,” says Gallo. The AGT800 laser thickness gauge, which was installed in February 2015, was just the solution Gallo needed.

With over 30 years in the service center industry, Gallo’s knowledge of gauging technology spans three decades and his search always led him back to A.G.T. “There was never any question,” he says of his decision to go with the Plain City, Ohio, instrument maker for Nova’s gauging needs.

Gauging instruments, he says, is “a market that has fewer and fewer players because of its difficult technology, but A.G.T. has a lot of experience and a wealth of knowledge. In the last 30 years, I’ve dealt with about 11 of their gauging systems.”

Steve Venters, sales manager at A.G.T., confirms, “We have known Vince for many years. In fact, he bought several of our very first AGT400 isotope thickness gauges more than 15 years ago. He’s been familiar with our gauges from his experience at other steel service centers.”

Instant results

When it came to the slitting line at Nova Steel, Gallo selected the AGT800 laser thickness gauge which is designed to measure the thickness of metals and virtually any other material processed in coil, sheet or strip form.

Introduced in 2013, the AGT800 offers a safer, improved alternative to isotope and X-ray gauging systems. The AGT800 has no radioactive source, compared to an isotope gauge. This means there are no requirements for compliance with federal and state regulations and radiation leak tests are not necessary.

“The isotope is a great gauge but we were able to get the same capabilities without all the legislative requirements that come with the isotopes. The software is also exactly identical. So, of course, we skewed to the AGT800; it became the first [one in use] in Canada at the time,” says Gallo.

The AGT800 is a two-part system comprised of an easy-to-install C-frame mounted on the processing line, and an electronics cabinet which contains the computer, electronics shelf, uninterruptable power supply, monitor and other key components. The AGT800 is designed to measure materials with a thickness range of up to 0.75 inch. It uses Keyence laser sensors that emit Class II laser beams which are received back on a RS-CMOS pixel array, or a photo sensor, and determines the distance to the target material. The gauge’s software uses this information to calculate the distance to the target material and precise material thickness is then determined. The AGT800 computer then translates the information instantly, automatically creating a coil report and various measurement data. This information is then stored on the gauge and can also be sent to a company server to avoid any loss in case of a power outage or other unforeseen incidents.

The S.P.C. reporting software collects and organizes the data to create detailed coil reports. The gauge also has sophisticated diagnostic screens which can make it much easier to diagnose any system problems that may arise. A.G.T.’s ISOcal system allows the gauge to check the calibration through sampling, which simplifies regular system checks. The report summaries are stored and saved onto Nova Steel’s hard drive and printed for technicians to analyze data.

“The gauge charts are very clear, concise and save to our hard drive automatically. We have it set up to not only save on the hard drive but it also creates a PDF to send to our sales team,” says Gallo.

Maximum accuracy

To instruct users on the complex technology, A.G.T. technicians offer detailed training support on the AGT800’s operation and maintenance requirements during the gauge startup. “When we commission a new system, it is typically a three- to four-day process,” says Venters. “We make sure everything is calibrated and everything operates correctly. Then, we meet with all the operators and maintenance personnel.” A.G.T. also performs semi-annual preventive maintenance checks in order to make sure the gauge is operating as designed.

“Every time A.G.T. comes in to do service work, they do a refresher for our maintenance personnel and operators. It’s a real benefit to us,” says Gallo.

Overall, the AGT800 has made Nova Steel’s operations more productive, he notes. Previous setup on the old gauge provided poor documentation, which created problems for Nova on gauge-related claims. “It’s a tremendous amount of money and time without gauge traces,” says Gallo, referring to the pickling line that ran with an older DMC gauge, which prolonged processing whenever the material was out of spec.

“We can now monitor gauge-related issues and crop accordingly. If a customer wants a gauge from 0.35 inch to 0.40 inch, and the material comes in 0.34 inch, we’re able to accommodate. Prior to this, you’d have to stop the line on several occasions.”

The AGT800 ensures measurements are accurate before shipping out any orders. “We can now say, ‘Supplier A, you’re supposed to send us 0.35-inch material and you sent us 0.33-inch.’ We have actual documentation showing any discrepancies,” explains Gallo. “If you don’t have any proof, you have to take a sample by hand. An average coil takes over 20,000 gauge points. Meanwhile, we can only do four or five by hand.”

Of A.G.T., Gallo says, “They are very professional and always willing to help us out. If you look at their products, they are very progressive and always finding ways to improve.”

After seeing positive results with the slitting line one month after installation, Gallo ordered an AGT800 for its outdated pickling line gauging device. The gauge is scheduled for installation during fall 2015. MM

Article by Gretchen Salois and appears in Modern Metals Magazine, September 2014

Above: A view of the AGT400’s C-frame from behind.

Optical sensors offer alternative to nuclear-based methods for thickness gauging

September 2014 – When talking radiation, red flags often pop up. News of reactor meltdowns and toxic leaks resulting in proverbial ghostlands like Chernobyl in Russia or seaside pollution in Fukushima, Japan, come to mind. But nuclear science serves a practical purpose when harnessed in a calculated and controlled environment.

Advanced Gauging Technologies LLC’s AGT400 isotope thickness gauge has been offered for the last 17 years and the company recently introduced its latest innovation in the form of the AGT800, a laser gauge the company believes will be the wave of the future for gauging thickness. Knowing the exact dimensions of material being processed can be both cost and time saving.

“Most service centers pay for their metal by weight. If the material they receive from their supplier is not the right thickness—let’s say they order 0.18 inch and receive 0.187 inch—they can end up overpaying or having to deal with an excessive amount of scrap,” says Steve Venters, sales manager for the Plain City, Ohio-based instrument maker.

The need for improved and reliable accuracy is only growing, especially in the aerospace, automotive, military and high-end electronics markets, adds Venters. “Many of these customers require reports and charts to verify the material thickness they receive is within specifications. The reports generated by a thickness gauge can also help a service center gain and maintain their ISO certification. Choosing a supplier that is ISO certified can often be a requirement for many end users.”

The major difference between the AGT400 and AGT800 is the method by which the gauges measure material thickness. The isotope gauge uses a radioactive source, Americium 241. This radioactive source is harnessed in a controlled environment and is enclosed in a source head located beneath the material being measured. Gamma rays are emitted when the source head’s shutter opens.

“The rays, which pass through the material are measured by a detector head located above the material which contains an ionization chamber,” Venters explains. “The gamma rays then ionize the gas atoms in the chamber and an electrical current is created. The AGT400 uses a unique algorithm and proprietary software to convert this electrical current into an accurate measurement of the material being processed.”

The AGT400 is best suited for material ranging in thickness from 0.007 inch up to 0.25 inch. “It depends upon the exact material being measured,” Venters says. The upper limit can also be increased to 0.312 inch thick when a larger ionization chamber is used in the detector head. It has a proven accuracy range of +/- 0.20 percent or +/- 0.0005 inch. Typically, the operating environment and the type of line the gauge is located on have no significant impact on the gauge’s accuracy.

The laser approach

Unlike the AGT400, the optical based system of the AGT800 laser gauge relies on advanced Keyence laser sensors to measure a material’s thickness. The Class II sensors are similar to the same sensors that scan bar codes at a retail store. “They do not generate heat and you can easily place your hand between the sensors and not feel a thing,” Venters says. “There are two sensors, one located above the material and one below it.” Each sensor sends a beam of light that strikes the material, which is then reflected back to the sensor’s receiving mirrors.

“The sensors know exactly how far each beam has traveled and they also know the exact distance between each other,” Venters continues. “This information is used to calculate with extreme accuracy the thickness of the material being measured.”

A third sensor can be added when the material passing between the sensors is not level. Mounted alongside the top sensor, it is
used to determine the passline angle of the material and then calculates the angle and applies a correction factor.

The AGT800 is designed to measure materials with a thickness range of 0.04 inch up to 0.75 inch, “although there are options available to measure thinner gauge materials as well,” he adds. The accuracy range of the AGT800 is less than 25 microns (0.001 inch). It is also alloy insensitive—it can measure virtually any type of material in coil, strip or sheet form. “Because the AGT800 uses laser sensors instead of a radioactive source, there are no costly and time-consuming government regulations required, such as leak tests,” Venters says.

Both the AGT400 and AGT800 feature automatic SPC reporting, data storage and offline data analysis. Data is stored on the gauge itself and can also be stored on a network server for easy recall of reports, Venters says. These reports provide graphic representation of the strip thickness over a coil or sheet’s length. “Both gauges will notify the operator immediately when a material’s thickness is out of tolerance,” Venters says.

Regulatory requirements

Like any isotope gauge, the AGT400 is subject to state and federal regulations, which require AM241 be tested for leaks once every six months “or once every two years if the source is in storage and not in actual service,” Venters says.

The trade-off of not having to comply with regulatory reports with the laser gauge is that the AGT800 requires a cleaner and more stable operating environment than its isotope counterpart. “Since it is an optical-based system, it is more sensitive to excessive dust, scaling and oil lubricants that are often present on some processing lines,” Venters explains. “It also requires a more stable passline and material flow to ensure the laser sensors are not damaged during line start up and tailouts.”

Both AGT model gauges have two primary components, an electronics cabinet and C-frame. The electronics cabinet contains an industrial grade computer, electronics shelf, monitor, printer, keyboard and a heavy-duty backup batter unit. The C-frame is positioned on the processing line and includes either a source and detector head (AGT400) or laser sensors (AGT800). “The C-frame will also have two Photoeye sensors which allow the C-frame to know when it reaches the edge of a coil,” Venters says. “A tachometer is also used to measure the footage of the material being processed.” MM

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