Aco-japan TYPE 7144/3348D

Infrasonic Meter TYPE 7144/3348D is ultralow-frequency sound pressure level meter to measure infrasonic or aerial vibration generated by explosive eruption of volcanoes.Measurement of ultralow-frequency sound pressure is possible in the range 2Pa～632Pa and 0.1～100Hz.

Reduction of input impedance has been realized by the employment of ceramic sensor, which has then offered an environmental suitability such as long-term outdoor measurement.

Aerial vibration is rapid pulsation of air generated around the crater by the explosive eruption of volcanoes, which thus travels as low-frequency sound pressure.

Due to ultralow-frequency sound pressure, the aerial vibration can not be heard by human ear but easily vibrates the building walls or windows during the propagation, sometimes giving a big damage such as breakdown of windows.

Infrasonic Meter means air vibrations are generated when a rapid change in barometrical pressure happens in the crater because of the eruption of the explosion of the volcano, and the impact spreads as a sound wave.