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7.4
Sensor Setup
7.4.1
Sensor Sizes / Pipe Diameters
FM750 electromagnetic flow meter converter matching sensor diameter range: 0.5” - 120” / DN15 - DN3000:
• 0.5”, 0.75”, 1”, 1.25”, 1.5”, 2”, 2.5”, 3”, 4”, 5”, 6”, 8”, 10”, 12”, 14”, 16”, 18”, 20”, 24”, 28”,
32”, 36”, 40”, 44”, 48”, 52”, 56”, 60”, 64”, 68”, 72”, 76”, 80”, 88”, 92”, 96”, 100”, 104”,
108”, 112”, 116”, 120”
• DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80, DN100, DN150, DN200,
DN250, DN300, DN350, DN400, DN450, DN500, DN600, DN700. DN800,
DN900, DN1000, DN1100, DN1200, DN1300, DN1400, DN1500, DN1600, DN1700,
DN1800, DN1900, DN2000, DN2100, DN2200, DN2300, DN2400, DN2500,
DN2600, DN2700, DN2800, DN2900, DN3000
7.4.2 Excitation Frequency Selection
The FM750 converter provides 6 modes of excitation frequency selection (the default setting of the
instrument is a 50Hz power supply mode, excitation frequency 6.25Hz). However, the user can choose from
the following according to the actual situation:
• 50Hz power supply mode: 3.125Hz, 4.167Hz, 6.250Hz;
• 60Hz power supply mode: 1.667Hz, 2.500Hz, 5.000Hz;
Small diameter sensor excitation system has a small inductance and high excitation frequency. Large
diameter sensor excitation system has large inductance; users can only choose low excitation frequency.
During use process, first select the low excitation frequency. If the zero point of the flow velocity of the meter
is too high, then select the low excitation frequency in turn. NOTE: The meter must be capable of operating
in the excitation frequency setting to which the unit has been calibrated. If high frequency excitation is used,
please order a high frequency excitation converter and select the appropriate excitation frequency value
according to this principle.
7.4.3 Sensor Factor
The Sensor Factor is the electromagnetic flow meter calibration factor. This factor is obtained from the actual
calibration of the meter, and is stenciled onto the sensor plate. Users can input this factor into the FM750
converter parameter table.
WARNING:
This parameter has been preprogrammed into your FM750 mag meter and should not be
adjusted. Altering this value will effect the accuracy of the flow reading of your meter.
7.4.4 Flow Rate Correction
See Appendix I for details.
7.4.5 Sensor Code
The sensor code can be used to mark the factory time and number of the matching sensor to coordinate
with the setting of the sensor coefficient.
