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Tachometer / Ratiometer

Digital Tachometer


  • ■ Available with up to 100kHz signal.
  • ■ Moving average & predicted function.
  • ■ Available with teaching function for auto-scale of measured value.
  • ■ Comparative judgement & data output

Operation manual

Standard Specifications

Model Designation

471C - - - -

①Power supply

Code Power Supply Voltage
A AC100 to 240V
9 DC24V

②Comparative output

Code Power Supply Voltage
X No output
2 4 photo-MOS relays (HH, H, L, LL)

③Analog output

Code description Allowable load resistance
X No output ---
04 DC0 to 5V More than 1kΩ
05 DC0 to 10V More than 1kΩ
09 DC1 to 5V More than 1kΩ
29 DC4 to 20 mA Less than 510Ω

④Digital output

Code Optional Output
X No output
DN BCD (Open collector / NPN)
E0 RS-232C
E1 RS-485

General Specifications

Measurement examples Number of revolutions, Speed, Frequency, Instantaneous flow, Instantaneous power
Measurement input SIG1: No voltage contact or NPN open collector
 Contact capacity: DC12V 10mA,
 Open collector residual voltage: less than 3V
 Frequency: 0.0067Hz to 100kHz
 Pulse width: more than 5µs to more than 25ms (hinge on the frequency)
SIG2: Voltage Pulse
 Input resistance: Approx. 24kΩ, Input level: “L” = 0 to 1.5V, “H” = 4 to 30V
 Frequency: 0.0067Hz to 30kHz
Pulse width: more than 17μs to more than 25ms (hinge on the frequency)
Display Display1: Red or Green LCD, Character height 15.2mm
SV1, SV2: White LCD, Character height 7.6mm
Zero suppression function
Display range Display1: 0 to 999999
SV1, SV2: 0 to 999999
Decimal point Arbitrary setting (0 / 0.0 / 0.00 / 0.000 / 0.0000 / 0.00000)
Display scaling Parameter α  1 x 10-9 to 999999 x 10-0
Display accuracy +/- (0.008% + 1digit)
Display cycle 0.1 to 19.9 s
Cut-off time 0.1 to 150.0 s
Number of moving averages 1 to 10 times
Sensor power supply DC12V +/- 10%, 80mA (built-in)
Supply voltage AC100 to 240V (50/60Hz), DC24V
Voltage tolerance of power supply AC90 to 250V, DC24V +/- 10%
Power consumption AC100V: Approx. 9VA
AC200V: Approx. 12VA
DC24V: Approx. 200mA
Operating ambient environment 0 to 50℃, 40 to 85 %RH (No condensation)
Weight Approx. 300 g
Protection Front operation unit: IP65
Rear case: IP20
Terminals: IP00

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