Chip Emery's World is Round

Testing, Testing

In the world of MTS, two of the most important words are “force” and “control.”

Start with force. “Every machine we make essentially applies a force and/or a torque to a product made by one of our customers to determine how strong it is or how long it will last,” says Dennis Harvey, a mechanical engineering manager who has been with MTS for 27 years. “Then we measure and adjust, measure and adjust, from 1,000 to 5,000 times a second.”

A tour of MTS’s 420,000-square-foot Eden Prairie facility gives visitors a behind-the-curtain glimpse into the inner workings of products we tend to take for granted. In one section of a Home Depot–sized warehouse, car tires are thrust inside big steel donuts whose specially designed inner walls test tread durability and steering response. In another, a computer simulator mimics the forces and temperatures inside a jet engine that affect the material construction and attachment of rotor blades. MTS doesn’t do the actual testing of these products—it makes the testing machines that it ships to customers’ testing labs. In this facility, it’s testing its testing equipment.

Elsewhere at the plant, upon a wood platform hoisted 10 feet in the air, sits a treadmill used for testing Formula One and NASCAR racecars. Separate readings under each wheel and the body record wind speed and drag conditions as the track simulates a race. MTS’s treadmills cost millions of dollars but make up a small percentage of the total cost of a wind-tunnel testing system, Harvey says. The treadmills improve the accuracy of the wind resistance measurement in a wind tunnel.

These machines and many others make up a portion of MTS’s test-products segment, which comprises about 85 percent of the company’s total revenues and employs about 900 people—about 300 of them engineers—in Minnesota. (Globally, the market for testing machines generates $1.6 billion and grows at a rate of about 4 percent annually.) Its customers are manufacturers of aerospace equipment and ground vehicles and their suppliers, as well as road and building construction companies, plastic-product makers, and developers and manufacturers of orthopedic joints.

Some of MTS’s testing systems are so large that they must be built on site. Case in point: a blast-simulator system built in 2005 at the University of California–San Diego to test the effects of bombs on buildings and bridges. The company has also built earthquake simulators large enough to shake a full-scale multistory building. In 2004, MTS completed a $3.5 million seismic test machine at the University of Minnesota. The machine was paid for by an $81 million appropriation from the federal government, which has commissioned 15 earthquake research labs at universities around the country.

“In my mind, no one else could have built it,” says Carol Shield, a professor of civil engineering at the U of M, who worked with MTS engineers to adapt the company’s seismic testing machines to work in new ways. The machine at the university’s lab is the only one in the country that can test the movement of large-scale buildings in many different directions. “An earthquake moves back and forth and twists and bends buildings,” Shield says. Before the construction of the MTS machine, “you could only shake a building laterally. We can put much more realistic loads on our specimens.”

While testing equipment makes up MTS’s largest business, its sensors segment is its fastest growing, at 10 to 15 percent annually. This is the “control” part of the business. The segment began in 1984, when MTS acquired Temposonics, a New York sensor manufacturer. The sensors (most of which have kept the Temposonics brand name) use a magnetic force called magnetostriction to measure linear position or liquid levels. The momentary interaction of an electrical and magnetic field inside and outside the sensor tube produces a pulse that travels at sonic speed to the head of the sensor. This gives a very precise measurement of the level of a liquid or the linear position of a component. Unlike other methods of measurement, magnetostriction is not affected by heat, cold, or the movement of air or water currents, and the sensors aren’t prone to mechanical wear or breakdown, since they have no moving parts.