• Murphy


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
Specifications Drawer: 
  • 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)
Literature Drawer: 

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