【 Flow Meter 】 FM-500

Flow meter for two inputs


Providing an accurate net fuel consumption measurement by measuring the fuel flow in both the fuel supply line and return line with a single flow meter


  • Supports two flow detectors for both the supply and return
  • Measurement of fuel consumption: supply flow rate – return flow rate
  • High-speed response   Analog output updated every 1ms
  • Two-channel analog output   Instantaneous consumption and total consumption
  • USB data output   Display data can be output as USB data simultaneously with analog output
  • A single pulse conveniently output every 1mL for overall management of total flow
  • Insulation   Each input and output part is provided with isolation
  • Erroneous operation is prevented by a key lock function
  • Temperature and pressure measurement (option)
  • Added function for temperature-corrected volume flow rate

Introduction to Functions

【Measurement of the return】
For an engine with return, the fuel returning to the supply side will present difficulties for the measurement. It is best in this case to do the detection with a second detector installed on the return side.
Using the signals from the two detectors on the supply and the return as inputs, the FM-500 measures both the instantaneous consumption and the total consumption.



FM-500 Flow meter for two inputs

Display method 6-digit x 2 rows, character height approx. 14.2mm 7-segment LCD, green
Range of display and measurement
  Instantaneous flow and average flow
  of total time
-99.999 to 999.999 L/h
  Total flow -99999.999 to 999999.999 L
  Pressure ±100kPa (attained pressure)
  Temperature -20.0 to 80.0
Display refresh time 0.1s
Accuracy Excludes the accuracy of the sensor
  Instantaneous flow and average flow
  of total time
±100ppm (RD) ±2digit
  Total flow ±1digit
  Pressure ±0.5kPa
  Temperature ±0.5
Signal input
Number of inputs 2 inputs (R03-R8F: Tajimi Electronics Co., Ltd.), R03-PB8M plug
Supply voltage for the sensor 12V, both supply and return 100mA (max)
Flow sensor
  Output signal format A/B phase / UP/DOWN
  Trigger level 2.5V (74HC365 equivalent)
  Voltage resistance -5V to +15V
  Pull-up Pulled up to 5V by 4.7kΩ
  Input frequency 15kHz
Temperature sensor
  Element Pt100, 3-wire system, excitation current 0.2mA
Pressure sensor
  Input range 1-5V (3V = 0kPa
Contact input
Number of inputs 2 inputs (7.62mm-pitch terminal block)
Functions Total measurement input and marker input when shorted to COM terminal
Trigger level 2.5V (74HC14 equivalent)
Voltage resistance -5V to +15V
Pull-up Pulled up to 5V by 4.7kΩ
Pulse output
Number of outputs 1 output (7.62mm-pitch terminal block)
Output items 1P/mL: single pulse output for each 1mL increase in total flow
Output voltage 0-5V (0.5V (max) voltage drop at 1kΩ load)
Analog output
Number of outputs 5 outputs (BNC receptacle), instantaneous consumption and total consumption
Refresh time 0.1s (switching at 1ms for instantaneous consumption only)
Output range ±10V (using D/A 16-bit)
Accuracy ±0.1% (FS)
Allowable load resistance 10kΩ
Interface USB mini-B
(output of display values, and receiving at the PC side using general-purpose software)
General specification
Insulation Power supply input/sensor signal input and contact input/analog output and pulse output
Power supply input voltage (power) DC9V to 32V, 10W (max)
External dimensions (mm) W: 184 H: 70 D: 196 (excluding projecting parts)
Weight Approx. 810g
Operating temperature and
humidity range
0 to 40/85%RH or less (with no condensation)
Accessories 5m power cable (1), and sensor connectors (2)

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