Abstract: In an embodiment, an air conditioning system for managing a server room, which has first and second spaces separated from each other, in which a server is installed between the first and second spaces, and supply air flowed into the first space is heated by heat generation of the server, and flows out as return air via the second space, includes: a cold air generation device; an air supply fan; a first differential pressure gauge; and a control device. The cold air generation device generates supply air satisfying a predetermined condition. The air supply fan flows the generated supply air into the first space. The first differential pressure gauge measures a differential pressure of a static pressure of the second space with respect to a static pressure of the first space.

Abstract: A pressure indicator for indicating pressure of a pressure source. The indicator comprises a first reservoir which defines a first enclosed volume having a first inlet pipe for communication between the first enclosed volume and a first source of pressurised fluid. The first inlet pipe defines a nominal communication path length between the first enclosed volume and a first source of pressurised fluid. A member is provided in the first inlet pipe which defines one or more communication paths of greater length to that of the nominal communication path length.

Abstract: Methods and apparatus for sensing pressure are disclosed. One disclosed pressure measuring device comprises a pressure transmission catheter including a stem portion and a sheath fixed to the stem portion. The disclosed sheath comprises a wall defining a cavity that is in fluid communication with a stem lumen defined by the stem portion. The disclosed sheath has a first transverse extent and a second transverse extent that is different from the first transverse extent.

Abstract: A detector tube is supplied with air at an adjustable pressure balanced by at least two adjustable leak flow rates in the conduits 4 and 7 in order to adjust the position of ball in the tube. The possible manual inclination of tube between an extreme vertical position and position slightly inclined to the horizontal is a complementary means of adjustment. The detector tube can be used for the detection and measurement of micropressures and micro flow rates.

Abstract: A temperature compensating device is provided for a purge gas pressure monitoring system in which a piezometer line has an outlet end for submerging in a medium to be monitored and an opposite end for connection to a suitable pressure responsive instrument, with a purge gas supply connected to the line so as to supply purge gas as bubbles from the outlet end of the tube. A temperature detector device runs the length of the piezometer line to produce an output signal proportional to an average of the temperature along the length of the line. This may be a resistance temperature detector in the form of a U-shaped conductive wire with opposite legs of the U wound spirally in opposite directions along the length of the line with the connected end of the U being located at the outlet end of the tube. This provides a variable resistance which varies as a function of the average temperature, and which can be connected to conditioning circuitry for producing a desired temperature dependent output.

Abstract: A pressure sensor of the present invention can perform pressure measurements under very severe mechanical and thermal conditions. It comprises a cell carrying a strain-measuring circuit. The cell is placed inside a body and is put into contact with the pressure to be measured. The cell has a hermetically sealed internal chamber inside which pressure is set to a predetermined reference value. The outside surface of the cell is subjected to the pressure to be measured. The cell is constituted by two half-shells joined together according to a join plane. The cell is preferably made of sapphire, with the crystal axis of the sapphire being perpendicular to the join plane so as to obtain isotropic stresses. A strain-gauge circuit is deposited on a plane surface of one of the half-shells, parallel to the join plane. The sensor is particularly suitable for testing oil deposits.

Abstract: The balancing-vessel transducer disclosed consists of a structure or housing enclosing two intercommunicating chambers part-filled with a liquid, and made freely rotatable about a horizontal axis coinciding substantially with its center of mass. One such chamber is in receipt of a pneumatic signal, while the remaining chamber is held at a constant reference pressure, such that liquid is displaced from one chamber to the other, thereby occasioning a redistribution of mass; the structure responds by rotating, its movement being checked by a force of reaction that varies in proportion to the force of the pneumatic signal, and turns through an angular distance that can be sensed in the shift of an eccentric pin attached to the structure itself.

Abstract: An apparatus for measuring fluid pressures which comprises a gas-type pressure sensor and a sensor control for supplying controlled purge gas to the sensor and for receiving vent gas from the sensor. The apparatus further includes a unique pressure-reducing device operable in response to a differential gas pressure in the sensor control for creating a zone of pressure less than any other in the apparatus, which zone is placed in fluid communication with gas in the apparatus to reduce the overall pressure thereof. This permits the accurate measuring of pressure at or below atmospheric. An integral design and a retrofit design are disclosed.