Pressure sensor

摘要

A pressure sensor has a detecting unit configured to detect a difference between outputs from deformation detecting units of first and second pressure variation sensors. The first and second pressure variation sensors are connected to one another so that the gap of the first pressure variation sensor communicates the exterior of the cavities of the first and second pressure variation sensors and the interior of the cavity of the first pressure variation sensor, and so that the gap of the second pressure variation sensor communicates the interior of the cavity of the first pressure variation sensor and the interior of the cavity of the second pressure variation sensor.

主权项

1. A pressure sensor comprising:
a first pressure variation sensor and a second pressure variation sensor, the first pressure variation sensor and the second pressure variation sensor each including: a cavity having an opening end; a cantilever formed into a plate shape extending in a direction from a proximal end to a distal end and including a proximal end portion supported at the opening end of the cavity in a cantilevered manner and a distal end portion as a free end, the cantilever being configured to undergo flexural deformation in accordance with a pressure difference between the interior and the exterior of the cavity; a gap provided between the distal end portion of the cantilever and the opening end of the cavity and configured to communicate the interior and the exterior of the cavity; a deformation detecting unit configured to detect a flexural deformation of the cantilever and output a signal of a result of detection; and a detecting unit configured to detect the difference between outputs from the first pressure variation sensor and the second pressure variation sensor, wherein the first pressure variation sensor and the second pressure variation sensor have lower limit frequencies which provide sensitivities of the first pressure variation sensor and the second pressure variation sensor equal to or higher than a predetermined value as the effectively same frequency characteristics in accordance at least with the capacity of the cavity and the distance of the gap, the gap of the first pressure variation sensor communicates the exterior of the cavities of the two pressure variation sensors and the interior of the cavity of the first pressure variation sensor, and the gap of the second pressure variation sensor communicates the interior of the cavity of the first pressure variation sensor and the interior of the cavity of the second pressure variation sensor.