
FDT-25W Wall Mounter Ultrasonic Flowmeter
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4.5 How to use the totalizer multiplier
Use window M33 to select a proper totalizer. Make sure that the totalizer pulse is appropriately
speeded. It should not be too fast and neither too slow. A speed of producing a pulse in several
seconds or minutes is preferable.
If the totalizer multiplier is too small, there can be a loss of accumulation pulse because the output
device can output only one pulse in a measurement period (500milliseconds)
If the totalizer multiplier is too large, the output pulse will be too fewer for the devices that are
connected with the instrument for a quicker response.
4.6 How to open or shut the totalizers
Use M34, M35 and M36 to turn on or turn off the POS, NEG, or NET totalizer respectively.
4.7 How to reset the totalizers
Use M37 to reset the proper totalizer.
4.8 How to restore the flow meter with default setups
Use M37, when the ‘selection’ message is displayed. Press the dot key first and the message ‘Master
Erase’ will display, then press the backspace key ◄
The master erase step will erase all the parameters entered by the user and setup the instrument with
default values except “instrument factor” and “network identification number” parameter
4.9 How to use the damper
The damper acts as a filter for a stable reading. If ‘0’ is entered in window M40, that means there is no
damping. A bigger number brings a more stable effect. But bigger damper numbers will prevent the
instrument from acting quickly.
Numbers 0 to 30 are commonly used for the damper value. Default value is 10 seconds.
4.10 How to use the zero-cutoff function
The number displayed in window M41 is called the lower flow rate cut-off value. The flow meter will
replace these flow rate values that are absolutely less than the low-cutoff value with ‘0’. This means the
flow meter will avoid any invalid accumulation when the actual flow is below the zero-cutoff value.