75
Sensor setup
used:
Area x Velocity = Flow.
See Submerged Pressure 770XXX manual for sensor details.
6.3.1 Submerged area/velocity sensor programming
1.
From the Main Menu, select
OPTIONS, LEVEL SENSOR.
2.
Select Submerged Xducer using the
CHANGE CHOICE
key, then press
ACCEPT
.
3.
From the
MAIN MENU
, select
SETUP, MODIFY SELECTED ITEMS.
4.
Highlight Velocity Direction using the
UP
and
DOWN
keys. Press
SELECT
.
5.
Set the velocity direction (upstream, downstream, or always positive) using the
CHANGE CHOICE
key. Press
ACCEPT
to continue.
6.
Highlight Velocity Units using the
UP
and
DOWN
keys. Press
SELECT
.
7.
Set the Velocity Units (fps or m/s), using the
UP
and
DOWN
keys. Press
ACCEPT
to
continue.
8.
Highlight Velocity Cutoff, using the
UP
and
DOWN
keys. Press
SELECT
.
9.
Read the Velocity Cutoff information screen. Press any key to continue.
10.
Set the Velocity Cutoff using the numeric keypad. Press
ACCEPT
.
11.
Set the Velocity Default, using the numeric keypad. Press
ACCEPT
. Press
RETURN
to
go back to the Setup Menu or the
MAIN MENU
to return to the Main Menu display.
6.4 Submerged pressure sensor
The submerged pressure sensor contains a submerged pressure transducer that
measures level in an open channel flow stream.
The submerged pressure sensor is mounted in the flow stream at the proper location for
level measurement. As the level in the channel increases and decreases, the pressure at
the submerged sensor varies proportionately. The pressure transducer converts the water
pressure to a voltage. The sampler uses the voltage to calculate the liquid level in the
channel. After calculating the level, the sampler then converts the level reading to a flow
rate based on the user-defined characteristics of the installed primary device.
The transducer in the submerged sensor first reads the pressure in the channel, then at
regular intervals, switches to a reference port to compare it to the atmospheric pressure.
This pressure difference is converted to a number which represents the liquid level. At
regular intervals, both the pressure transducer diaphragm and the reference port are
switched to atmosphere together. Then they are electronically zeroed to eliminate any
drift due to changing barometric pressure.
6.4.1 Submerged pressure sensor connection
The submerged pressure sensor connection is located on the left side of the controller
housing and is labeled submerged pressure sensor. The connector is keyed and can only
be inserted in the proper orientation (key up).
Goodnal STP ST041 Pre Treatment (Sigma 900 MAX All Weather Refrigerated Sampler) Vendor Manual
Q-Pulse Id VM373
Active 29/10/2013
Page 75 of 122
