In the 1800s, mathematician Gaspard-Gustave de Coriolis predicted the effect that the earth’s rotation would have on a fluid in motion. But it was quite some time before Micro Motion founder Jim Smith figured out in 1977 how to empirically measure that effect and use it to calculate the fluid’s mass flow rate. The earliest Coriolis meters were primitive by today’s standard, relying on analog electronics—including the rotary optical encoder enshrined in the brand’s original logo—to determine the vibrational frequencies and amplitudes necessary to calculate a meaningful mass flow rate.
But Micro Motion was formed just as digital tools began to revolutionize not only the speed and sensitivity of the Coriolis meter’s electronic circuitry, but also the design of the vibrating tubes themselves. In pursuit of ever more accurate meters, finite element analysis (FEA) was used to model and study the mechanical aspects of the meters, even as computational fluid dynamics (CFD) was called on to simulate the fluid flows within.
“We were among the earliest users of FEA and CFD to figure out how fluid flows and structures interacted,” says Mark Bell, vice president of engineering, Coriolis technology, Emerson. “Back then it was airplane manufacturers and Micro Motion."
So began a sustained, user-driven campaign to push the accuracy and range of its meters to unprecedented levels—achieving the industry standard 0.05% of mass flow ratings embodied in the company’s ELITE Series meters that debuted in 1992.
Proof of performance
But it wasn’t just digital designs and simulations that made such performance possible. The organization simultaneously invested tens of millions of dollars in the sophisticated test facilities needed to validate those meters’ performance. “We partnered with National Laboratories for guidance, and now have some 15 flow stands accredited by the International Organization for Standardization (ISO) to 0.01% accuracy,” Bell says. “Today, our capabilities are more extensive than any national flow lab in the world.”
Strategically located near customers across the Americas, Europe and Asia, these facilities serve both engineering and product development tasks—often across Emerson’s flow measurement portfolio—as well as proving grounds for its customers’ unique fluids and multiphase concoctions. “They’re half engineering labs and half for specific customer applications,” Bell explains. “On any given day we may be testing beer, toothpaste, fire retardant, or oil mixed with water.” Custody transfer applications are particularly test-worthy, as billions of dollars of product may pass through a single Coriolis meter over the course of its lifetime.
It’s also extremely important to pair any given fluid with a sensor tube made of the appropriate alloy, to avoid corrosion, erosion or other effects that can pose safety or reliability risks. “We have a team of metallurgists on staff and use a range of stainless steels, exotic alloys and titanium, depending on the fluid in question. Our compatibility guidelines run into the hundreds of pages, and are based on our 45 years of experience with what metals can be used with what fluids.” For example, titanium may be a super metal when it comes to many corrosive materials, Bell says, “but it doesn’t do well with even dilute concentrations of bleach. It’s important that we know that.”
Pushing the envelope
“Our customers continue to ask for meters that can take higher operating temperatures and pressures; they’re adjusting their processes to get higher efficiency or improved yields,” Bell adds. So, new designs that push the traditional limits of Coriolis meters are rigorously tested using shaker tables, environmental chambers and burst chambers with over-pressurized meters to ensure they’ll operate as promised. “If we say it’s going to operate at 800 °F, it’s going to operate at 800 °F—as one of our recently released meters does,” Bell says. “We rely on proven engineering practices from design through test to ensure that a meter will not be a reliability concern, and that it will exceed performance expectations.”
In the rare event that a Micro Motion meter does show signs of deteriorating performance—normally detected through the meter’s onboard diagnostics before posing a safety concern—Emerson’s labs are also equipped to get to the root cause of the problem. “All of our different locations have full sectioning capabilities, plus stereo and video scopes and scanning electron microscopes,” Bell says. “We also have electron dispersive microscopes (EDMs) to examine any pitting mechanisms in great detail.”
These labs are often co-located with the companies’ service centers and key Coriolis manufacturing facilities in Boulder, Colorado (the original Micro Motion headquarters in the U.S.); Chihuahua, Mexico; Nanjing, China; and Cluj, Romania. And while most early Micro Motion meters were manufactured on demand, today they’re assembled from regionally stocked sensor, transmitter and flange subassemblies to meet customers’ specific requirements in a timely fashion. This local presence for final assembly and test also streamlines delivery of finished devices.
“Being physically close to our customers has always allowed us to better support their needs,” Bell says. “And with today’s supply chain issues and environment concerns, that proximity is more important than ever.”
