Ultraflux Uf 811 CO, User Manual, Page: 43 / 106

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NT UF 811 CO GB (c) / March 2014
5.4.4 "Level settings" menu
This menu is dedicated to configuring the level measurement.
The level measurement is essential for measuring the flow. In fact, ultrasonic probes are used to measure
the average flow velocity of the fluid in the channel and the level is used to find out the surface wetted by
the fluid in the section of the channel.
1) Number of level measurements
The UF 811 can be used to manage up to four level measurements.
The menu below is used to select, for each level, the input channel which corresponds to the level
measurement (for example, a 4-20 mA input):
The measurement used to calculate the flow rate (priority measurement) is level 1. If this is faulty, the flow
meter automatically switches to level 2.
Note: To measure a level, a simple solution involves using a current input. The flow meter will work out the
level of water in which the sensor is submerged from the current measured. Simply configure the range of
the sensor and the base of its scale. For further information on the configuration of inputs/outputs, see the
chapter dedicated to this subject.
Comment: For a level sensor taking a downward measurement (for example, a measurement by ultrasound
in the air), the range of the measurement entered in the flow meter must be negative.
5.4.5 "Hydraulic Profile" menu
1) Description of the hydraulic profile
The vertical hydraulic profile is described using 20 sections.
Each section is defined by its lower and upper elevations and by its hydraulic coefficient (see this concept in
our document "Flow measurement by transit time difference").
The value of this coefficient may be fixed section by section (absolute mode) or may be calculated for each
section based on the distance from the section to the surface.