Tachometers and Tach/Hourmeters
Tachometers and Tach/Hourmeters


  • 4000 RPM –0 to 100,000 hours
  • Sensing from magnetic sensor, battery charging alternator or ignition signal
  • High visibility analog readout
  • Air core movement
  • Easy calibration through dip switches
  • Through dial lighting
  • Powered by 11-28 VDC battery available


The AT Series tachometers are rugged, transistorized instruments with solid-state circuitry for indication of engine RPM. They are equipped with a bracket for mounting into a standard 3- 3/8 in. dash mounting hole. A full 270° sweep of the pointer gives an accurate indication on a large easy–to–read scale and the dial can be illuminated for night reading. The ATH Series models are also equipped with hourmeter to record the elapsed running time of an engine.


Models available for Alternator, Magnetic Sensor or Ignition signal These instruments are designed to function from pulses generated by an alternator with 4, 8, 12, 14, or 16 poles on the rotor. The pulses can also be obtained from the ring gear of an engine by means of an electromagnetic sensor (magnetic pickup). Murphy’s magnetic sensor driven models are designed to function with flywheels having anywhere from 50 to 304 teeth. Ignition signal model available for 4, 6 or 8 cylinder, spark-ignited engines. All models are for negative ground, positive ground or isolated electrical systems and are protected against reverse polarity hookup.



These tachometers are specially designed for use on truck, marine, industrial, or stationary engines.

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