PURPOSE: To make it possible to set working pressure readily by using a pressure sensitive element in the semiconductor sensor part of a pressure sensor, sensing the pressure, and making the threshold value formed by resistance voltage division variable.
CONSTITUTION: A pressure sensor F, which uses, e.g. a piezoresistive pressure sensitive element as a semiconductor sensor part (a), is provided at the lower side of a signal processing printed circuit board 5, which is arranged in a main body 1 having pressure introducing ports A and B in two directions facing to each other up and down. A base part 3 of a resin stem 2 of the sensor F is sealed in the inner bottom part of the main body 1 with an O ring 6. The pressure, which is introduced through the introducing port A, is sensed by the sensor part (a) by way of the gap of the stem 2, the space formed in the main body 1 and the through hole of the base part 3. The pressure through the introducing port B is sensed by the sensor part (a) by way of a vertical hole 4 provided at the central part of the base part 3. The pressure is transduced into the electric signal, and the signal is taken out with a terminal rod 8. The voltage of the electric signal is varied by a variable resistor, and the working pressure can be readily set. Furthermore, the simple mechanism as the pressure which is obtained at the low cost.
KAJI NORIKIMI
HORI MASAMI
NISHIMURA HIROMI
