When you only prepare a feast once a year, serving your guests a roast that is as lovely to behold as it is to consume can be elusive. Even with Wi-Fi connected or Bluetooth capable temperature sensors strategically stabbed into the bird, we’re likely stressed about duplicating the delicacy served by our forebears. Maybe we should have paid more attention when Grandma was in charge? Can technology be an impediment to developing rudimentary skills? In the delivery of useful measurements and controls, we’ve experienced similar challenges.
Not long ago a magnetic flowmeter—seemingly a wise choice for a weakly acidic stream—began fluctuating erratically, causing its associated control valve to also behave badly. As the secondary, a.k.a. “slave” loop of a cascaded level control, it was in manual for a week or so before the valve was just directly connected to the level controller. The question arose, "why was this configured as a cascade loop anyhow?" The answer was familiar: “Because we could.” When adding a plethora of alarms to a control loop or creating a cascade pair requires only mouse clicks, we can be guilty of deploying technology for technology’s sake.
Our propeller-head tendencies can lead to choices that sound nifty and clever, but end up adding little value for the end user. Do we need a $10,000 magmeter with self-checking diagnostics? Perhaps a close-coupled DP flowmeter will suffice at a fraction of the price. And if it’s not part of the control scheme, i.e., indicate-only, its impact is lower if it freezes up or fails. When the boiler tripped on low steam drum level, the plant manager asked, “Didn’t you train them on those controls?” Yes, but a split-range control scheme that cleverly supplements make-up boiler feedwater for recycled condensate could become befuddling to novice operators. Perhaps we should let them manage it manually.
You can hire a $2,000/day consultant to make a stakeholder map for you, or just ask yourself, who will be impacted (i.e., suffer) most from my choices? In most instances, it’s operations, but it’s important to involve maintenance as well. Maintenance—your instrument specialists—might tip the scales toward a more mundane solution, something they know well. Process engineers, environmental specialists and accountants can also have meaningful input about reliability and accuracy. If we allow our hobbies and/or isolation to preempt or neglect their needs, our duty to wisely invest the company’s capital is tarnished.
There are plenty of easy applications for which stock solutions are adequate, or even ripe for experiments or innovation. But making prudent choices for the remaining 10-20%, or the “once a year” challenges that are both consequential and expensive to remedy, that’s when our depth is tested. If we’re the individual on the team that the remainder trusts to prevent operational indigestion, we can’t rely on blaming the vendor when pain ensues.
In some instances, a complex measurement technology can create a distraction regardless of its importance. The superheated steam overpressure vent is shut, but the flowmeter’s output is erratic once the static line cools to saturation temperatures. Even after decades of experience, would anyone have foreseen that the sensor technology, effective in always-superheated service, would be subjected to saturated or even condensing conditions? Even long-time practitioners find themselves responsible for the occasional turkey.
If we don’t engage the coming generations of measurement and controls professionals in the kitchen from an early age, their ability to make choices that optimize fitness for purpose will be greatly diminished. As corporations have cut in-house staff and outsourced non-core competencies, process control has not been immune.
Grandma didn’t need a lot of instrumentation to roast a turkey, and would most likely find modern attempts to improve on basic kitchen skills useless, if not ridiculous. If she’s still able to give us some guidance, let’s learn while we can. In like manner, let’s make the most of the experienced professionals among us before their combat-hardened experiences are out the door.
