Another parameter called profile factor expresses the chord velocity factors as a ratio, inner
velocity factors over outer velocity factors: B+C
A+D, a number which should always exceed one (> 1).
The exact value of this profile factor varies with the flowmeter’s installation, and may shift over
time if the flow profile shifts for some reason (e.g. partial blockage in a flow conditioner, piping
change, accumulation of debris on pipe wall). For example, a pipe accumulating dirt or other solid
material on its walls over time will tend to slow down the velocity of fluid near the walls compared
to the velocity of fluid in the center. This has the effect of decreasing chord A and D velocity ratios
while increasing chord B and C velocity ratios, which in turn increases the profile factor value. In
this regard, the profile factor value for an operating flowmeter may be an important diagnostic tool,
indicating some physical abnormality within the piping