PURPOSE: To sustain ventilation and waterproofness at a port opened to the atmosphere even for severe outer environment.
CONSTITUTION: The pressure sensor comprises a housing 1 having a port 11 opened to the atmosphere, a pressure sensor chip 2 disposed in the housing 1 so that the atmospheric pressure is received through the port 11 on one side 2a thereof while a pressure to be detected is received on the other side 2b thereof and the pressure difference is detected in the form of a strain, and a sensor circuit 3 for converting the strain of the pressure sensor chip 2 into an electric signal. The port 11 opened to the atmosphere is applied with a ventilative waterproof filter 4 communicating with the atmosphere through a passage 51 having an opening 51b in the direction perpendicular to one side 4a of the filter 4. Since the opening 51b is communicated with the atmosphere through a bent passage 51, the filter 4 is not directed directly to the outside of the housing 1 and protected against direct attack of physical external factor, e.g. mud or a pebble.
KAJI NORIKIMI
HORI MASAMI
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