Nearly all of the deadtime in pressure loops comes from the automation system. For gas pressure there is a process time constant or integrating process gain that becomes slower as the volume increases and the throughput decreases.
Compressor surge is the fastest gas dynamic phenomena. A precipitous drop in flow occurs in 0.05 seconds and subsequent flow reversals occur every 1 to 2 seconds. The speed of response requirements for control valves, measurements, and controllers are extraordinary.
The maximum level controller gain for stability is one or two orders of magnitude higher than expected. The main limit to how high you can go in controller gain is often measurement noise and control objective.
pH is the most common analytical measurement. pH is important for product purity and environmental compliance. The most stringent pH control requirements occur in bioreactors for biopharmaceuticals where a deviation of 0.05 pH can cause a noticeable degradation in mammalian cell growth rate and product formation rate.
Sat in on a Web presentation this morning over the phone. (Love the Webexes of the world. Much better than burning days in an airport boarding lounge.)
From the press release: In 2008, TiPS celebrates 20 years in the field of alarm management. It all started with a seemingly innocent consulting job to, "Do something about that @#!& printer!" The solution was a custom-written software program, widely recognized today as LogMate.
Hi Walt, Enjoyed seeing you in Park City. I think we'll be back next year... The discussion at the Tuesday night dinner regarding the state of the engineering profession spawned a thought in my mind. I'd like to offer a [slightly] different perspective on the situation, still sensitive to the...