Tokyo Keiki UFL-30, Installation & Operation Manual

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III- 52
III-5-5. Other
5.1 What is the foremost advantage of ultrasonic flow measurement over other types of flow
measurement?
(1) The equipment can be installed on existing pipes without interrupting flow and as
such is ideal in applications involving facilities management.
(2) Transducers are non-intrusive and do not obstruct flow or cause head losses.
(3) There is no great cost difference relative to pipe size diameter so compared
to other types of measurement, it is comparatively low cost when large diameter pipes are
involved.
5.2 Can the equipment be linked to telemeters or higher order computer systems?
As unified DC 4 - 20mA output signals for momentary flow are provided, the equipment can be
linked with other types of measurement equipment. Also the exchange of totalized flow data can
be accomplished through relay pulses. If BCD code output is desired, you can specify an optional
BCD converter. In addition, RS232C output is also provided.
5.3 Does maintenance involve a lot of work?
As the hardware does not employ any moving parts, there is no need for lubrication, scouring, or
mechanical adjustments. Electronic circuits include long life solid state CPU’s and IC’s which do
not require daily maintenance. See Chapter III-1 ‘Maintenance and Inspections’.
5.4 Even with pipe diameter and flow volume information, isn’t the calculation of flow velocity
cumbersome?
Certainly, determining cross sectional area from the diameter of the pipe, and dividing flow volume
by the cross sectional area to calculate flow velocity may be a bit troublesome. This task can be
aided by the graph in Chapter III-4-1, ‘Flow volume and Average Flow Velocity’. The vertical axis
of the graph is the average flow velocity, the horizontal axis - the flow volume, and the diagonal
lines represent various pipe diameters. As an example, for a pipe diameter of ø600mm, find the
applicable diagonal. If the flow volume is 1,000 m
3
/h, proceed up from the horizontal scale at
1,000 m
3
/h, until you intersect the ø600m diagonal and then angle 90° to the left to the
corresponding point on the vertical scale to determine flow velocity. In this case, flow velocity will
be 1m/s. For full scale flow, operating flow, and minimum flow volumes, it is simpler to consider
these in terms of flow velocity and use of the graph in Chapter III-4-1, ‘Flow Volume and Average
Flow Velocity’ is recommended.