When it comes to flowmetering systems in your facility, what is the best way to measure its true performance?In a Flow Control magazine article, R & R: How reproducible is your highly repeatable metering system?, Emerson’s Karl Stappert, of the Flow Solutions team, addresses these important concepts—repeatability and reproducibility.
Karl opens defining the two terms. Repeatability is the sensor’s ability to provide the same flow indication [repeatedly] at unchanging process conditions. These conditions include flow rate, fluid properties, temperature, and pressure to name a few. He defines condition of repeatability: a condition, out of
…a set of conditions, that includes the same measurement, same operating conditions (process and ambient), same location, and replicate measurements on the same object over a short timeframe.
Measurement device product specifications:
…often called accuracy, is achieved under specific conditions of repeatability.
The issue is, of course, that operating plants rarely have these conditions of repeatability. Unlike a calibration laboratory, they are constantly changing. Karl notes that repeatability is one of the most discussed statistical quality measures used for measurement instruments and that turbine meters are one of the most repeatable flow measurement technologies available. Continue Reading ▶