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FDT-25 Handheld Ultrasonic Flowmeter
3. How To
§3.1 How to judge if the instrument works properly
When ‘R’ is displayed in the lowest right corner of LCD display, the instrument is working properly,
generally speaking.
If an ‘H’ flashes on that place, there could be poor signal received. Please refer to the chapters
on diagnosis.
If an ‘I’ is displayed, it means that there is no signal detected.
If a ‘J’ is displayed, it means that the hardware of this instrument could be out of order. Refer to
the chapter on diagnosis.
§3.2 How to judge the liquid flowing direction
(1) Make sure that the instrument works properly
(2) Check the flow rate for the indication. If the displayed value is POSITIVE, the direction of
the flow will be from the RED transducers to the BLUE transducers; if the displayed value is
NEGATIVE, the direction will be from the BLUE transducers to the RED transducers;
§3.3 How to change between units systems
Use menu window M30 for the selection of unit system in English or Metric system.
§3.4 How to select a required flow rate unit
Use menu window M31 to select the flow unit first and then the timing unit.
§3.5 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.
§3.6 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.
§3.7 How to reset the totalizers
Use M37 to reset the proper totalizer.
