Special Configurations - Accusonic 8510+ series Reference Manual

ENV
LEVEL
CHNL
BITS

Special Configurations

Occasionally, it may be necessary to configure the meter in a "non-standard" mode to meet a particular
requirement. This section contains special configurations.
Using Layer Boundary Parameters to Simulate a Round Pipe
When a "compound flowmeter" is set up in a pipe, the shape of the pipe has to be described using the Layer
Boundary parameters. If the pipe is round, a large number of possible ways of describing its shape in terms
of trapezoidal layers can be devised.
The following table gives one possibility, which has the merits of giving very close approximations to the
wetted area, with only 11 numbers to be calculated. The maximum errors occur when the stage is below 0.1
x Pipe Diameter. This is below the lowest layer and likely to be below the lowest path, and so of no
relevance. At a stage of 0.05 x Pipe Diameter, the error is 4.5% of actual area. For stages between 0.1 and
0.2 x Pipe Diameter, the errors are less than 0.2%. Above 0.2 x Pipe Diameter, the errors are small.
All Path Elevations in terms of measured distance above the channel bottom.
Separating Forward and Reverse Flows, (For Pump / Generating Plant)
For some full pipe systems, it may be desired to compute separate totalizer counts (from relay closures) and
volumes for forward and reverse flows. To achieve this, two sections should be configured, using the same
paths, but with slightly different section parameters. In this example, Section #1 is for forward flow, and
section #2 for reverse.
Parameter
Path Enable
Pipe Area
screen 1-5.
The travel times of the overall signal envelopes for both the Forward (left column)
and Reverse (right column). Note: this is used for diagnostic purposes. Displayed on
screen 1-6.
The time-averaged value of each individual Level input, the elevation of the water
surface above the site datum.
The second 4-digit number after the Level value is the instantaneous value of analog
input. It is scaled so that an input of 0.00 volts is displayed as 0, and 5.00 volts as
4094.
If the input resistor fitted is the nominal 100 (Standard), the 4 digit number will be
scaled so that: 0mA is displayed as 0, 4mA as 328, 20mA as 1638, and 50 mA as
4095. Displayed on the path variable screen 3.
Layer Boundary Elevation
Zero x Diameter
0.05 x Diameter
0.20 x Diameter
0.40 x Diameter
0.60 x Diameter
0.80 x Diameter
0.95 x Diameter
1.00 x Diameter
Section #1 Section #2
1111000000 1111000000
Actual Value -Actual value
User Defined Parameters
Layer Boundary Width
0.116 x Diameter
0.472 x Diameter
0.823 x Diameter
0.993 x Diameter
0.993 x Diameter
0.823 x Diameter
0.472 x Diameter
0.116 x Diameter
Comment
Both the same
Section #2 will read negative
negative.
7-11