Abstract: A flow resistor includes a housing, a pipe, and an adjuster. The housing includes a through hole including a first hole portion and a second hole portion. The pipe includes a first extending portion and a second extending portion that extends in a direction different from an extending direction of the first extending portion. The adjuster includes a through hole. The pipe is inserted into the through hole of the housing, the first extending portion is positioned in the first hole portion, and the second extending portion is positioned in the second hole portion. The adjuster is positioned in the second hole portion and is a member movable toward the second extending portion. The through hole of the adjuster couples a space between the adjuster and the pipe with an outside of the flow resistor, in the second hole portion.

Abstract: A gas leak sensing device includes a constant flow rate control valve, a pressurization control valve, a supply-side gas circuit, a master-side gas circuit, a workpiece-side gas circuit, an equal pressure valve, an exhaust valve, a test pressure sensor, and a differential pressure sensor. The supply-side gas circuit is connected with the constant flow rate control valve and the pressurization control valve. The equal pressure valve performs opening and closing between the supply-side gas circuit and the master-side gas circuit and opening and closing between the supply-side gas circuit and the workpiece-side gas circuit. The exhaust valve performs opening and closing between the workpiece-side gas circuit and outside. The test pressure sensor detects pressure in the supply-side gas circuit. The differential pressure sensor detects a differential pressure between the master-side gas circuit and the workpiece-side gas circuit.

Abstract: A gas leak sensing device includes a constant flow rate control valve, a pressurization control valve, a supply-side gas circuit, a master-side gas circuit, a workpiece-side gas circuit, an equal pressure valve, an exhaust valve, a test pressure sensor, and a differential pressure sensor. The supply-side gas circuit is connected with the constant flow rate control valve and the pressurization control valve. The equal pressure valve performs opening and closing between the supply-side gas circuit and the master-side gas circuit and opening and closing between the supply-side gas circuit and the workpiece-side gas circuit. The exhaust valve performs opening and closing between the workpiece-side gas circuit and outside. The test pressure sensor detects pressure in the supply-side gas circuit. The differential pressure sensor detects a differential pressure between the master-side gas circuit and the workpiece-side gas circuit.

Abstract: A flow resistor includes a housing, a pipe, and an adjuster. The housing includes a through hole including a first hole portion and a second hole portion. The pipe includes a first extending portion and a second extending portion that extends in a direction different from an extending direction of the first extending portion. The adjuster includes a through hole. The pipe is inserted into the through hole of the housing, the first extending portion is positioned in the first hole portion, and the second extending portion is positioned in the second hole portion. The adjuster is positioned in the second hole portion and is a member movable toward the second extending portion. The through hole of the adjuster couples a space between the adjuster and the pipe with an outside of the flow resistor, in the second hole portion.

Abstract: In a calibration mode, an equilibrium period after pressurized gas is sealed in a device under inspection and a reference tank is divided into two periods; pressure-difference changes ?P1 and ?P2 are measured when a first-half equilibrium period of duration T1 elapses and when a second-half equilibrium period of duration T1 elapses, respectively; and a pressure-difference change ?P3 generated in an inspection period of duration T2 is measured. A pressure-difference change CT2 generated for duration T2 from when a period of time in which the influence of an adiabatic change seems to become sufficiently stable elapses is measured. A drift correction coefficient K is calculated from these measured values using K=(?P3?CT2)/(?P1??P2), is stored in a storage section, and is used in an inspection mode.

Abstract: A method for detecting an operation malfunction of a leakage inspector causes the leakage inspector to execute a calibration process and an inspection process. The calibration process seals air inside a first device serving as a reference device and measures changes in pressure over two time intervals. The inspection process seals air inside a second device to be checked for a leak and measures changes in pressure over two time intervals. A ratio is calculated from these measured changes in pressure and the ratio is used to determine whether an operation malfunction occurs in the leakage inspector.

Abstract: In a calibration mode, an equilibrium period after pressurized gas is sealed in a device under inspection and a reference tank is divided into two periods; pressure-difference changes ?P1 and ?P2 are measured when a first-half equilibrium period of duration T1 elapses and when a second-half equilibrium period of duration T1 elapses, respectively; and a pressure-difference change ?P3 generated in an inspection period of duration T2 is measured. A pressure-difference change CT2 generated for duration T2 from when a period of time in which the influence of an adiabatic change seems to become sufficiently stable elapses is measured. A drift correction coefficient K is calculated from these measured values using K=(?P3?CT2)/(?P1??P2), is stored in a storage section, and is used in an inspection mode.

Abstract: In a calibration step, air is sealed in a first device serving as a reference device; a pressure change B1 in the first device at a point elapsed a predetermined period of time from the air sealing, and a pressure change B2 at a point further elapsed the predetermined period of time are measured; and these pressure changes are stored. In an inspection step, air is sealed in a second device to be checked for a leak; pressure changes B1? and B2? corresponding to the pressure changes B1 and B2 are measured after the air sealing; and a waveform ratio K is calculated from these measured values as (B1??B2?)/(B1?B2). It is decided whether a malfunction occurs in a leakage inspector by using the value of the waveform ratio K.

Abstract: A seal ring having rounded-corner rectangular shape in cross-section is mounted in a recessed groove formed in ring configuration in a pressure-contact surface of a seal jig such that major axis of the seal ring is oriented perpendicular to the pressure-contact surface and the seal ring is projected out the pressure-contact surface by about 15-35% of length of the major axis to be compressively deformable in the direction of the major axis, and stoppers formed of low thermal conductivity resin are disposed on the pressure-contact surface, the peripheral portion of the opening of an article being tested is brought into pressure-contact with the seal ring in a manner such that the stoppers are interposed therebetween and that the compressively deformed seal ring provides an adequate sealing effect to seal the opening, whereby testing may be conducted without bringing the article being tested into contact with the seal jig.

Abstract: A flow resistance setting nozzle capable of easily setting a target flow rate is provided. A metallic block has a through-bore through which a flow path forming metallic pipe is inserted. A pressing member in the form of a rectangular cross-section bar abuts the pipe at a first abut portion. An anvil having a distal end with an arcuate surface is mounted to the metallic block such that the distal end abuts the pipe at a second abut portion that is opposite to the first abut portion. A coarse adjustment screw presses a center portion of the pressing member against the pipe to squeeze the pipe between the pressing member and the anvil to form an orifice in the pipe. Two fine adjustment screws impart a force to the pressing member to further squeeze the pipe until the target flow rate is set.

Abstract: In a leak test method and apparatus which introduces high-pressure gas into a work and a master from a high-pressure gas source through first and second electromagnetic valves, respectively, closes the first and second electromagnetic valves, detects the pressure difference between the work and the master by a differential pressure sensor, and compares the amount of leakage, obtained from the pressure difference, with a leakage reference value to thereby decides the work to be leak-free or leaky, a third electromagnetic valve is provided which permits and inhibits the passage of gas between the work and the master.

Abstract: A micro-leakage regulating valve, in which a metal block has a through hole and a tapped hole extending from one side of the metal block and communicating with the through hole at the center thereof. The through hole has inserted therethrough a capillary metal tube. At one end of the through hole a sealing member provides a seal between the outer peripheral surface of the capillary metal tube and a surrounding wall surface of the metal block. An adjusting screw is screwed into the tapped hole, to crush the capillary metal tube to a desired degree, setting a desired flow rate.

Abstract: An apparatus for measuring a flow rate of a fluid such as a gas, having a by-pass passage, a measurement passage, a cantilever-shaped pressure-receiving plate in the measurement passage and a deflection detector for measuring an amount of deflection of the pressure-receiving plate.

Abstract: An apparatus for measuring a flow rate of a fluid by a cantilever type pressure receiving plate which is disposed within a flow channel such that a substantially perpendicular fluid flow abuts against the surface at one end portion of the plate so that the cross-sectional area of said fluid flow opposing the end portion of the plate is increased when the end portion of the plate is deflected by the acting forces of the fluid flow.