7088-8000
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Low Flow Cutoff (Menu 34)
When a zero flow condition occurs (for example, as
the result of a pump being shut off), internal sloshing,
check valve leakage, and other fluid movement can
prevent the flowmeter from reading total zero. This
phenomenon can result in totalizer errors.
These errors can be minimized by entering a low flow
cutoff (a minimum acceptable value for flow) in this
menu. Setting a low flow cutoff drives the flowmeter
to zero for flow rates at or below that value. If the flow
rate (regardless of direction) falls below the low flow
cutoff value, the instrument’s indicated flow is driven
to zero and the totalizers stop incrementing.
For example, if a low flow cutoff of 0.1 foot per
second (.03 meters per second) is entered, the
instrument would be driven to zero for flow rates less
than 0.1 foot per second in the positive direction and
greater than -0.1 foot in the negative direction
(Figure 3-2).
-0.3 -0.2 -0.1 0 +0.1 +0.2 +0.3
Zero flow
displayed here
Figure 3-2 Low Flow Cutoff (example)
NOTE:
The default setting for the low flow cutoff is
1.0.
Low Signal Cutoff (Menu 35)
Empty pipes or solids, bubbles, or voids in the flow
stream may cause temporary drops in signal strength
and erroneous readings. The effect of these dropouts
can be minimized by setting a low signal cutoff.
Setting a low signal cutoff (a minimum acceptable
signal amplitude), drives the flowmeter to the
loss-of-signal (LOS) condition.
Low Flow Cutoff
0.00 GPM
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