Abstract: A oxygen-production device includes a pulse-tube cryocooler for cooling air to liquefy oxygen, and a main container for obtaining and retaining liquefied oxygen. The main container has a heat regenerator, a cold head, and a pulse tube of the pulse-tube cryocooler therein. A temperature sensor measures a temperature of the liquefied oxygen, and a control device controls an output of the pulse-tube cryocooler according to the temperature measured by the temperature sensor.

Abstract: A oxygen-production device includes a pulse-tube cryocooler for cooling air to liquefy oxygen, and a main container for obtaining and retaining liquefied oxygen. The main container has a heat regenerator, a cold head, and a pulse tube of the pulse-tube cryocooler therein. A temperature sensor measures a temperature of the liquefied oxygen, and a control device controls an output of the pulse-tube cryocooler according to the temperature measured by the temperature sensor.

Abstract: The present invention is directed to a capacitive differential pressure detector comprising a diaphragm disposed between two electrodes. In a first embodiment, each of the electrodes comprises two conductive plates with an insulator disposed therebetween. Step-like portions are formed in the conductive plate nearest the diaphragm. In a second embodiment, the plate nearest the diaphragm is insulative with a conductive film formed thereon. In a third embodiment, at least one groove is formed in the plate nearest the diaphragm. The groove is formed in a surface of the plate which faces the diaphragm. The groove also intersects a pressure guide hole. In a fourth embodiment, a substrate is disposed on a surface of the plate farthest from said diaphragm. In a fifth embodiment, an insulating layer has the same coefficient of thermal expansion as the conductive plates. In a sixth embodiment, the diaphragm is etched in order to form a circular flexible part, a centrally disposed displacing part, and a bonding part.

Abstract: A pressure detector for measuring the pressure of a pressurized fluid by means of electrostatic capacitance comprising a diaphragm displaceable in response to the pressure, and a pair of fixed electrodes, one of each of the fixed electrodes being located on each side of the diaphragm and being electrostatically capacitively coupled to the diaphragm, each of the fixed electrodes being shaped to essentially eliminate electrostatic capacitances that are not differentially linear with respect to the pressure.

Abstract: An electrostatic capacity type pressure detector having a central diaphragm, which is deformed by pressure, and a fixed electrode on each side of the diaphragm. Each of the fixed electrodes includes a first electrically conductive plate confronting the diaphragm, an insulating plate joined to the first conductive plate, and a second electrically conductive plate joined to the first plate. An annular support joined to the diaphragm and to the insulating plate surrounds but is insulated from the first electrically conductive plate. A hole in the electrode introdues pressure into a space defined by the electrode and the diaphragm.