Ultraflux Uf 811 CO, Руководство пользователя, Страница: 34 / 106

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NT UF 811 CO GB (c) / March 2014
5.2 Main configuration elements
5.2.1 Geometric and physical definition of the measuring point
1) Composition of a measuring point
A measuring point consists of:
 an open channel measurement section (channel or river),
 a description of the hydraulic profiles,
 a fluid,
 one or more ultrasonic chords,
 up to four level sensors (which may or may not be provided by Ultraflux).
2) Reference systems used
Two reference systems are used:
 The customer reference system: the one used in measurement mode to display the water level.
"Level" is used to refer to all elevations measured in this reference system,
 The section description reference system: the one used to describe the form of the channel or the
river. "Height" is used to refer to all elevations given in this reference system.
Example: The water is at 150 mm on a water level gauge. The flow meter will display the level of the water
surface in the customer reference system.
However, to describe the section, you may wish to take the bottom of the channel as a reference, with the
water level to be displayed in relation to the customer reference system. The joint use of the two reference
systems then involves reference planes.
3) Definition of the reference planes
Each channel is defined by a set of trapeziums. Each trapezium is defined by:
 height at top/height at bottom,
 width at top left and right/width at bottom left and right.
To define the section of the channel, two reference planes are used, one for the heights (H0) and one for
the width (W0). The form of the channel or the river is broken down into sections. Each section represents a
part of the trapeziums. The heights and widths of the trapeziums are measured in relation to two reference
planes.