Dynasonics TFXP Series Transit Time Ultrasonic Flow Meter - Manual (Page 84)

Rev. 5/09
-4.6- TFXP
The Damping value is increased to improve stability of the flow rate
readings. Damping values are decreased to allow the flow meter to
react faster to changing flow rates.
Low Flow Cutoff is entered as a percentage between MAX Flow
and MIN Flow and influences how the meter will act at flows very
close to zero. Generally, an entry of 5% provides a stable zero
indication.
Low Signal Cutoff is a relative value that should be entered after a
successful startup. For an initial value, enter 5%. (Signal Strength
indications below 2% are considered to be below the noise ceiling
and should not be indicative of a successful flow meter startup.)
The Low Signal Cutoff has three purposes:
1. It provides an error indication – Low Signal Strength (Error 0010
on the TFX display) when liquid conditions within the pipe have
changed to the point where flow measurements may not be
possible.
2. It warns if the pipe’s liquid level has fallen below the level of the
transducers.
3. It can also signal that something with the flow meter installation
or configuration may have changed. For example, the couplant
used to mount the transducer has become compromised, a
cable has been disconnected or a pipe size has been altered.
Exponent Display Multiplier
E-1 × 0.1
E0 × 1 (no multiplier)
E1 × 10
E2 × 100
E3 × 1,000
E4 × 10,000
E5 × 100,000
E6 × 1,000,000
Table 4.1 — Totalizer Exponent Values
PART 4 - SOFTWARE UTILITIES