Vibrograph

Vibrograph for motor transformer
What is Vibration Auditory Sensitivity?

The term “auditory sensitivity” generally refers to division of the value measured by a noise level meter into characteristics A, B and C to bring the result close to sounds heard by the human ear.

ECG Kokusai’s Motor Vibrophonic Monitor (MV-90) detects motor vibrations by a vibration sensor, electrically amplifies these vibrations to produce a sound transmitted from a speaker, enabling the operator to determine the status by ear and sounds close to the actual sound of the motor revolution are realized by using high and low filters. In the broad sense, this can be thought of auditory adjustment.

However, since, although the sensor directly detects the motor rotation noise, in the case of a noise level meter, the motor rotation vibration cause the ambient air to vibrate, in turn, causing an extremely light trembler in the microphone to vibrate, and this energy is converted into an electrical signal, MV-90 is not fully-compatible with noise level meters specified for meters, for example.

Nevertheless, as long as the unit is operated within the specified range, correlation should be achievable. This makes this a product that can be used as a substitute for noise level meters within the specified range.