5
Signet 0250 Setup Tool
AVERAGING Only
With AVERAGING set to 60 seconds and SENSITIVITY set to
100%, the fl ow rate is stabilized, but a sharp change in fl ow rate
is not represented for 60 seconds or longer. This can cause
system problems if one of the operating setpoints falls within this
range.
AVERAGING and SENSITIVITY
With AVERAGING at 60 seconds and SENSITIVITY set to 25%,
the fl ow rate is stabilized, but the sudden shift in fl ow is refl ected
very quickly.
No AVERAGING, no SENSITIVITY
With AVERAGING set to 0 (zero) the SENSITIVITY is ineffective,
and the fl ow rate may be very unstable. This will cause the output
signals to respond erratically.
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Magmeter Averaging and Sensitivity Settings
Because ideal fl ow conditions are often impossible to acheive, the fl ow rate is often erratic, which in turn causes any control features
(ie; relays, 4-20 mA loops, etc.) that are associated with the fl ow rate to also be erratic.
The best solution to these problems is to correct any piping defi ciency that causes the instability. This may involve longer straight runs
upstream, reducing the pipe size to maintain a full pipe at all times, and other installation changes. In many situations, however, these
measures are simply not possible.
The Magmeter provides several tools that are designed to "work around" these defi ciencies. They are called "Performance Settings"
and can be modifi ed only through the 3-0250 Setup Tool. The noise rejection and the Low Flow Cutoff settings are self-explanatory. The
Averaging and the Sensitivity features should be studied before making adjustments.
Averaging Time in Seconds (Factory set: 14 seconds)
• Set the time the Magmeter will use as the averaging period.
With averaging at 14 seconds, each display is an average of the previous 14 seconds input.
Use higher averaging times to smooth the display and current output where the fl ow in the pipe is erratic.
Quick Response Sensitivity (Factory set: 25% of Maximum Range, or 2.5 m/s)
• Set the percentage of change in the fl ow rate required to allow the Magmeter to override the AVERAGING and jump to a new fl ow
rate immediately. (maximum range is 10 m/s)
The pictures below illustrate the effect of these settings.
