The new TD101 SmarTach + D combines a wireless tachometer, Diesel tachometer and a secondary ignition voltage tester into one hand held tool. The digital tachometer measures up to 20,000 RPM, on engines with 1 to 12 cylinders, 2 or 4 cycles. With gasoline engines, it works by sensing the electromagnetic waves from the ignition system, and requires no contact with the engine, eliminating the need for test leads, inductive pick-ups or reflective tape. For diesel engines it uses a sensor that is connected on the fuel injection line, where it senses the “pulse” of the injector. The secondary ignition voltage tester provides a digital readout of the spark plug wire voltage, enabling the technician to quickly detect and troubleshoot of problems in ignition systems. Simply by hooking the antenna sensor to the spark plug wire, it measures peak voltages up to 40000V. This unit includes a cable and 6 mm diesel sensor adapter, User’s Manual, and a 9 V battery.