Principles of Operation
Vortices are created when a fluid passes around a bluff body as shown in
illustration (click Images Tab above). Vortices are alternately shed on
each side of the body, 180 degrees out of phase to each other,
resulting in an oscillating pressure gradient. As flow increases the
frequency of vortices increases in proportion to the increased flow
thereby creating a linear relationship.
General Description
Constructed of type 304 or 316 stainless steel, wafers may be installed
in-line by customer provided or built-in flanges. Key pad or
communication interface functionalities include Measuring units,
programmable flow alarm, two programmable totalizers, programmable flow
rate pulse output, two programmable optically isolated outputs, battery
backed real time clock (RTC), digital communication interface (RS-232 or
RS-485), programmable diagnostic events log and register with date and
time stamp, programmable process variable log with date stamp,
calibration and flowing fluid parameters adjustment, extensive
diagnostics.
Aalborg's unique dual signal processing technology
independently measures each vortex on either side of the bluff body and
filters out non-flow noise. This results in less noise and higher
accuracy throughout the flow range.
Local 2x16 LCD readout
provides flow rate and total flow volume reading in selectable
engineering units, diagnostic events indication and feature a password
protected access to the process parameters to ensure against tampering
or resetting.
