Boulder, CO— Emerson Process Management's Micro-Motion division recently introduced a patented "in-service" Coriolis flowmeter verification procedure that uses density measurement to confirm that the flowmeter's flow-tube structure remains unchanged. The in-service procedure ensures that the meter's mass-flow calibration factor remains valid and minimizes needless recalibration. [See related Back to Basics, in this issue, on custody transfer.]

Micro Motion's verification procedure requires periodically filling the flowmeter with a fluid of a known density and comparing it to the density measurement reading of the flowmeter. Using the two values, variability is calculated to assess the accuracy of the mass-flow calibration. In cases where the process fluid's density is known and stable, the procedure can be performed with the process flowing and the unit in normal operating mode.

The procedure doesn't eliminate the need to remove, decontaminate, ship, and recalibrate a flowmeter. However, it does provide a quantified diagnostic means of ensuring only those flowmeters needing recalibration are removed.

For more information, visit www.emersonprocess.com/micromotion.