Flo-Ware Manual - Hachflow

Device communication
Option
Delay time
Target sets
(Target set
averaging)
Description
The time paused between the repeats to assure distinct target sets are
captured. The factory default is 2500 ms (2.5 sec). The user may enter other
values. The optimal delay time value depends on the level and velocity.
Deals with velocity measurement noise caused by the non-uniform
distribution of moving targets in typical waste water flow streams. This target
noise can be reduced by averaging several readings based on distinct target
sets. There are several options for averaging:
• Robust filtering–sorts velocity readings from highest to lowest and
averages the middle values
• Reject drops–excludes outliers at low absolute velocity
• Reject spikes–excludes outliers at high absolute velocity
• Lo Freq Rej–Low Frequency Rejection may be useful to eliminate noise
in highly turbulent sites where swirling occurs at the nose of the sensor
10. Click on the Advanced Settings tab.
11. Change the application setting, if necessary.
12. If the velocity and flow are known, a site multiplier can be generated to calibrate the
velocity.
a. Click the CALCULATE button. The Velocity Multiplier window opens.
b. Click TAKE SAMPLE. The velocity measurement starts. When complete, the
measured velocity is shown.
c. Measure the velocity with a different instrument and enter the value in the Actual
Velocity field. The multiplier value adjusts the sensor reading to be the same as
the actual velocity value.
d. Click OK.
13. Change any of the settings for velocity if necessary:
Option
Site Multiplier
Low Level
Cutout
Substitute
Velocity
Filter Size
Salinity
Description
The value that adjusts the sensor velocity reading to be the same as the
velocity reading from a different instrument. If not sure, use the default value
of 1.0.
Forces the velocity to a substitute value when the level measurement is
below a user-specified value. The factory default is enabled at 0.8 inches.
The value of the substitute velocity (typically 0).
Select the type of filter and the filter size (factory default is none). Takes the
average and/or median of 3, 5, 7, 9 or 11 data points to reduce noise or
outliers. Only the average and/or median values are logged—raw data
values are not logged. A significant delay can occur before sudden changes
in flow are logged, therefore this option is not recommended for stormwater
applications.
Select wastewater, salt water or enter a user defined value. Factory default
is wastewater.
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