The FT-7200 Advanced Tachometer is an easy-to-use handheld digital tachometer offering high functions and performance. The use of FFT (Fast Fourier Transform) technology enables the FT-7200 to perform frequency analysis of rotation speed by using change of signal in sound, vibration or magnetic flux from rotating machines such as a motor or the like. Selection from 5 kinds of measurement modes allows it to calculate and display rotation speed of any complex waveform signals from a sound level meter or an accelerometer accurately by extracting the exact frequency component.

The FT-7200 enables non-contact measurement of rotation speed by sound or vibration from a measurement object with inaccessible rotating shaft such as a built-in motor in a product, which disabled using conventional tachometers. No need for affixing a reflection mark or modification to a rotating shaft of a measurement object.

Also the use of new algorithm allows calculation and displaying with high follow-up performance, even a sudden change of rotation speed in rising/falling edge of a motor or accelerated/decelerated engine rotation, which has been disabled with conventional models. The FT-7200 is a battery-operated and easy to carry handheld tachometer facilitating on-site measurement.

The FT-7200 can be used with various optional detectors by Ono Sokki; microphone and sound level meter, accelerometer and engine vibration detector, ignition pulse detector and so on. In addition, the FT-0801 cigarette lighter socket sensor is available for detecting voltage output from power outlet in vehicle. Selectable from wide range of detectors depending on your requirements.

Rpm measurement  from vibration

Rpm measurement
from cigarette lighter socket sensor

The rotation speed of an engine can be measured from sound or vibration caused by the movement of pistons. This is an effective measurement method when an engine compartment is covered, and engine rotation sensors cannot be attached.

• Set the number of pulses to match the number of ignition firings per one crankshaft rotation.
  Example: In the case of a four-cylinder engine with four-cycle, the number of pulse is set at 2 P/R.

This example shows how to measure rotation speed of DC motors that are built in home appliances. Rotation speed of a motor deeply inside in home appliance, such as an electric toothbrush, can be obtained by magnetic flux leaking from the motor.

• The rotation speed can be measured simply by inputting the number of poles in a DC motor rotor.

The rotation speed of an engine can be measured by clamping a sensor to the primary side of low-voltage or secondary side of high-voltage conductor. Measurement can be performed simply by inputting the number of ignitions per rotation.

• Set the number of pulses to match the number of ignition firings per one rotation.
  Example: In the case of a 4-cycle engine
  If you will be performing measurement on the primary conductor, set the number of pulses to half the number of cylinders. If you will be performing measurement on the secondary conductor, make the setting 0.5 P/R so that there is one pulse for every two rotations.

This example shows how to measure rotation speed of an engine from an vehicle's muffler noise. Since pulsation component of engine rotation is included in muffler noise, the engine's rotation speed can be obtained by this pulsation frequency component.

• Set the number of pulses to match the number of ignition firings per one crankshaft rotation. Please note, however, that depending on muffler performance, there may be cases when measurement cannot be performed.