The Murphy Selectronic MT90 digital tachometer offers high accuracy and dependability resulting from use of a quartz crystal time-base and digital, solid-state electronics.

Tachometer power is supplied by either a Murphy magnetic pickup mounted at the flywheel ring-gear of an engine or by a 12-, 24- or 32-volt DC battery system. RPM data is supplied by either a Murphy magnetic pickup or by the alternator in your battery charging circuit. The MT90 tachometer also has backlighting for easy readings in low-lit areas. The MT90 is calibrated to engine RPM by setting a series of calibration rotary switches on the back of the tachometer. Typical applications include: generators, compressors, industrial engines, oil field equipment, marine vessels, vehicles, farm equipment and construction equipment.

Specifications Downloads How To Order
  • Signal Input Voltage: 4 to 35 Vrms from a magnetic pickup or alternator*
  • Pulses per Revolution: 3 to 999

Power Requirements

  • Pickup Power: 4-35Vrms*
  • Battery Power: 8-40 VDC (12, 24, 32 volt)


    • Tach backlight Off, 4mA @ 40 VDC
    • Tach backlight On, 25 mA @ 40 VDC
  • Case: 1018 polycarbonate/polyester blend
  • Lens: Polycarbonate Bezel: #430 Stainless Steel
  • Display: LCD, 4-digit, seven segment
  • Operating Temperature: -4° to 158°F (-20° to 70°C)
  • Storage Temperature: -13° to 185°F (-25° to 85°C)
  • Mounting Hole: 3-7/16 in. (87 mm)
  • Shipping Weight: 14 oz. (0.4 kg)
  • Shipping Dimensions: 5-1/2 x 5-1/2 x 5-1/2 in. (140 x 140 x 140 mm)

 WARNING: This product may expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information about California Propsition 65, go to or visit our California Proposition 65 page.

Additional product documentation can be found on our product support website or by clicking the Help Center button above.

Part Number Model/Description Notes
20700019 MT90-1 MT90 with bright stainless bezel
20700193 MT90-1-B MT90 with black stainless bezel

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