Device for measuring sound level
A device for measuring sound level, comprising: an inlet opening; a MEMS microphone for measuring sound level; and an external acoustic attenuator with a pressure divider comprising: a first branch between the inlet opening and the membrane of the MEMS microphone via an inlet channel and a resonant cavity; and a second branch between the resonant cavity and a vent chamber via a vent channel.
1. A device for measuring sound level, comprising:
an inlet opening;
a MEMS microphone for measuring sound level; and
an external acoustic attenuator with a pressure divider comprising:
a first branch between the inlet opening and the membrane of the MEMS microphone via an inlet channel and a resonant cavity; and
a second branch between the resonant cavity and a vent chamber via a vent channel,
wherein the pressure divider comprises a dumping material layer mounted between the inlet opening of the external acoustic attenuator and the resonant cavity, wherein the resonant cavity splits to the inlet channel and a vent channel coupled with a vent chamber.
2. The device according to claim 1 , wherein the vent channel has acoustic impedance smaller than acoustic impedance of the inlet channel.
3. The device according to claim 1 , wherein the resonant cavity is filled with a material absorbing acoustic energy.
4. The device according to claim 1 , further comprising a TEDS memory storing information on an individual frequency characteristic of the device.
5. The device according to claim 1 , wherein the components of the device are positioned in a tight housing in the following order: an inlet opening of the inlet channel, a sealing set, the pressure divider, the resonant cavity, a PCB with the MEMS microphone, the vent chamber and a PCB with connector for coupling the device with external devices.
6. A device for measuring sound level, comprising:
an inlet opening;
a MEMS microphone for measuring sound level; and
an external acoustic attenuator with a pressure divider comprising:
a first branch between the inlet opening and the membrane of the MEMS microphone via an inlet channel and a resonant cavity; and
a second branch between the resonant cavity and a vent chamber via a vent channel,
wherein the components of the device are positioned in a tight housing in the following order: an inlet opening of the inlet channel, a sealing set, the pressure divider, the resonant cavity, a PCB with the MEMS microphone, the vent chamber and a PCB with connector for coupling the device with external devices.
7. The device according to claim 6 , wherein the pressure divider comprises a double-sectional channel, having a first inlet section which constitutes a portion of the inlet channel between the inlet opening of the external acoustic attenuator and the resonant cavity, and a second vent section which constitutes a branch of the first inlet section and is connected with the vent chamber.
8. The device according to claim 7 , wherein the vent channel has acoustic impedance smaller than acoustic impedance of the inlet channel.
9. The device according to claim 6 , wherein the pressure divider comprises a dumping material layer mounted between the inlet opening of the external acoustic attenuator and the resonant cavity, wherein the resonant cavity splits to the inlet channel and a vent channel coupled with a vent chamber.
10. The device according to claim 6 , wherein the resonant cavity is filled with a material absorbing acoustic energy.
11. The device according to claim 6 , further comprising a TEDS memory storing information on an individual frequency characteristic of the device.