Background

Mainstream PREMIER Fixed AV-flowmeter was commissioned for measuring flow at a bridge in Sweden with a non-standard profile. The location of the bridge was on a small river flowing a few kilometres downstream from Lake Mien in southern Sweden. There was a requirement to draw a freehand channel section to provide accurate flow measurement.

Bridge Section Sweden

Mainstream was provided with the bridge section dimensions:

Bridge Section Dimensions

Mainstream was also provided with an expanded profile of the mounting dimensions for the velocity sensor.

Mounting Rail

Mounting Rail

Method
Where a freehand drawing requires many coordinates it is advisable to either use a CAD system or draw this out in order to calculate the multiple points. Generate or calculate X/Y coordinates to all intersections.

Before proceeding to plot the coordinates using Mainstream Communicator and due to the intricacies of the dimensions, the computer mouse had to slowed significantly.

Open Mainstream Communicator and select Pipe Channel Section, then select Section Drawing.

Zoom In or Out according to the requirements of size of the drawing and select Set Origin.

Set the top left-hand corner of the drawing page to X=0 Y=0

Set Origin

Drawing View

Set Origin and Drawing View

Plot the channel profile using the X/Y coordinates that you have plotted on the
drawing.

Set origin X : 0mm
1. X : 90 Y : 1660
2. X : 180 Y : 1660
3. X : 180 Y : 1960
4. X : 2440 Y : 1960
5. X : 2440 Y : 1610
6. X : 2570 Y : 1610
7. X : 2620 Y : 0

To store this profile, start the logger and retrieve the logged file.

Pipe Channel Section

This file will save as a CSV file in the Mainstream / DATA directory and as an AV1 file in the Mainstream / ARCHIVE directory. The LOAD option will automatically lead you to the ARCHIVE directory and load the relevant file.

Premier Fixed AV-Flowmeter Graph

This graph shows the values from Mainstream PREMIER Fixed AV-flowmeter for a period of one week in situ utilising the freehand pipe/channel section.

Blue line is Mainstream Flow
Red line is Mainstream Level
Pink line is Mainstream Velocity
Green line is Mainstream Signal Quality