Sierra 240-VTP, 241-VTP instruction manual S T

Series 24-HP Instruction ManualAppendix B Glossary

Q R S T

Q	Flow rate, usually volumetric.
Rangeability	Highest measurable flow rate divided by the lowest
	measurable flow rate.
Reynolds Number	A dimensionless number equal to the density of a fluid
or Re	times the velocity of the fluid times the diameter of the
	fluid channel, divided by the fluid viscosity (i.e., Re =
	ρVD/∝). The Reynolds number is an important number
	for vortex flow meters because it is used to determine
	the minimum measurable flow rate. It is the ratio of the
	inertial forces to the viscous forces in a flowing fluid.
RTD	Resistance temperature detector, a sensor whose
	resistance increases as the temperature rises.
scfm	Standard cubic feet per minute (flow rate converted
	to standard conditions, usually 14.7 psia and 20°C).
Shedder Bar	A non-streamlined body placed into a flow stream to
	create vortices. Also called a Bluff Body.
Strouhal Number	A dimensionless number equal to the frequency
or St	of vortices created by a bluff body times the width of
	the bluff body divided by the velocity of the flowing
	fluid (i.e., St = fd/V). This is an important number for
	vortex flow meters because it relates the vortex fre-
	quency to the fluid velocity.
Totalizer	An electronic counter which records the total accu-
	mulated flow over a certain range of time.
Traverse	The act of moving a measuring point across the
	width of a flow channel.

U V W X Y Z

Uncertainty	The closeness of agreement between the result of a
	measurement and the true value of the measurement.
V	Velocity or voltage.
VAC	Volts, alternating current.
VDC	Volts, direct current.
VORTEX	An eddy of fluid.

IM-24-HP B-3