Advanced Tachometer FT-2500

Rotational speed measurement of a DC motor with the micro rotating shaft

The rotational speed of a DC motor can be measured without attaching the reflective mark on the surface of the shaft. This example allows the rotational speed measurement of the fan, which shaft is too thin that reflective mark can not be attached or optical light can not be reflected straight when optical sensor is used.

• Easy operation - just input the number of fan blades.
• Non-contact measurement - ideal for inspection line measurement.

Determining of rotating direction and rotational speed measurement of a general DC motor

It is an example to determine the rotating direction and measure the rotational speed of a DC motor by using the FT-0501 DC Motor Rotation Detector. The FT-0501 detects the magnetic flux leakage of a DC motor and extracts a frequency signal in proportion to the rotational speed.

Since the FT-0501 has two internal coils, a phase shift occurs between the two detected signals. The rotating direction is then determined by the relationship of these two phases. This function is very convenient for quality control of small DC motors, whose rotating directions may be difficult to be determined visually. Of course, it can measure the rotational speed.

• The direction of rotation can also be determined by the two phase output.
• The output function (semiconductor relay) that determines the rotating direction is useful for CW/CCW judgment on inspection lines.

Rotational speed measurement of a compressor using an accelerometer

With a combination of the FT-2500 and suitable accelerometer, the rotational speed of a compressor in the refrigerator, vending machine, air conditioner etc, which shaft is not directly accessible, can be measured easily. Put an accelerometer (NP-3000 series) on an optional magnet base (NP-0100 or NP-0101) and check the signal at various locations. And then place it at an optimum position on the compressor.

• Easily measure the rotation speed of a compressor even though its shaft is not direcly accessible.
• It can measure not only a compressor itself, but also a built-in final product.
• Suitable for lock judgment such as during a refrigerator lock test.

Rotational speed measurement of a DC motor in a fuel pump using a current probe sensor

Many DC motors are mounted in automobile electrical equipment. The consumption current of the DC motor pulses in proportion to the number of poles in the motor. The rotational speed of the DC motor can be accurately measured by inputting the current signal which is detected by the current probe sensor to the FT-2500.
This example is ideal for measuring the rotational speed of a stand-alone DC motor or products (parts) that incorporate motors whose lead wires are accessible, such as those found in automobile electrical equipment.

Rotational speed measurement of a pump using sound pressure

A pump’s rotational speed is easily measured by monitoring exhaust sound. The rotating shaft in a pump is generally not exposed externally, making it difficult to perform measurement of the rotational speed by the ordinary and conventional pulse detection method. In this example, the sound pressure of the exhaust sound is detected for the rotational speed measurement with a microphone.

• Easy operation - just input the number of blades.
• It can measeure the rotation speed of a pump even though its shaft is not directly accessbile.

Rotational speed measurement of a DC motor which is built in a home appliance

A popular electric toothbrush is operated by converting the rotation of the DC motor into the vibration. The FT-2500 with FT-0501 detector can measure the rotational speed by detecting the magnetic flux leaking from the DC motor which is built in such product.

• Detects the pulsation of the magnetic flux leakage in proportional to the number of poles of the DC motor which is built in the finished product.
• Provides two steps, upper-/lower-limit comparator output which is ideal for the determination such as OK, LOWER, or UPPER on inspection lines.
• Data management through RS-232C interface.

Rotational speed measurement of an engine using a microphone or an accelerometer

The FT-2500 can measure the rotational speed of an engine by the sound and vibration related to the movement of the pistons. It is effective when the rotational sensor cannot be attached because the engine compartment is covered.

• Set the number of pulses to match the number of ignition firings per one crankshaft rotation.
   (e.g.) Set at 2 P/R in the case of a four-cylinder engine with four-cycle

Rotational speed measurement of an engine using an engine rotational sensor

The rotational speed of an engine can be measured by clamping a sensor to the primary low-voltage or secondary 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.
   (e.g.) In the case of a four-cycle engine
  If you perform the measurement on the primary side, set the number of pulses at half number of cylinders.
  If you perform the measurement on the secondary side, set at 0.5P/R because one pulse is generated per two rotations.

Rotational speed measurement of a small fan using an accelerometer

It measures the rotation speed of a rotating body such as a small fan. The vibration of the rotating object depends on the rotational motion. By measuring the frequency of vibration, the rotational speed of the rotating object can be obtained.

Rotational speed measurement of an engine from muffler’s sound collected by a microphone

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

• 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 that measurement cannot be performed.

Rotational speed measurement of a vacuum cleaner using a sound level meter

>Even if a motor is not visible like a vacuum cleaner, it measures the rotational speed of a motor from the operating noise.

Rotational speed measurement of a dryer and an electric drilling machine using an accelerometer

By the rotational vibration, the FT-2500 can measure the rotational speed of a motor which is built into the dryer, electric drilling machine or the similar equipment even though the motor is not accessible.

Rotational speed measurement of an engine using a cigarette lighter socket sensor

Connect the sensor to a power outlet in a car or construction machine. With the FT-2500, you can determine rotational speed of the engine by measuring the ignition noise from the power outlet. Can be used with both 12 and 24 VDC batteries.

Simultaneous measurement of rotating speed and direction of a fuel pump

This example shows how to make rotating speed measurement and rotation direction determination of a finished fuel pump simultaneously, which is widely used such as in a vehicle. Since the rotating shaft is not come out, it is difficult to make direct measurement by attaching a sensor to the rotating shaft. The rotating speed and direction of the motor built in a fuel pump can be measured by the FT-2500 advanced tachometer with the FT-0501 magnetic flux leakage sensor. The FT-0501 attached to the fuel pump detects the magnetic flux leakage, and the FT-2500 performs frequency calculation of the magnetic flux changing periodically.