Patent attributes
A pressure sensor (1) includes a diaphragm (21) with a bottom formed of a thin-wall portion (210) and a pressure introducing joint (10), in which an austenitic precipitation hardening Fe—Ni heat resisting steel having high mechanical strength is used for the diaphragm (21), while an austenitic stainless steel that is relatively inexpensive is used for the pressure introducing joint (10). The diaphragm (21) and the pressure introducing joint (10) are integrated by welding, and Ni content of a weld portion is appropriately adjusted. Thereby, the pressure sensor (1) achieves high accuracy and reliability, and usage amount of the expensive austenitic precipitation hardening Fe—Ni heat resisting steel can be minimized in manufacturing the pressure sensor (1). Also, since the austenitic stainless steel has an excellent corrosion resistance, the pressure sensor (1) can be used in measurement of a fluid with high corrosiveness.
