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: A flow resistance setting nozzle capable of easily being set at a target flow rate is provided. Metallic block has pipe receiving through-bore through which flow path forming metallic pipe is inserted. Pressing member in form of rectangular cross-section bar is brought into abutment with pipe at a first abut portion thereof. Anvil having distal end with arcuate surface is mounted to metallic block such that distal end abuts with pipe at a second abut portion thereof which is opposite to first abut portion. Coarse adjustment screw presses pressing member at center portion thereof against pipe with coarse adjustment force to squeeze pipe between pressing member and anvil to form an orifice by coarse amount in the pipe. Two fine adjustment screws impart a fine adjustment force to pressing member to thereby further squeeze pipe by fine amount 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: A volume measuring apparatus comprises pair of tanks of substantially the same volume for supplying gas to a container to be measured and a refernce container, a pressurized gas source for filling the pair of tanks with gas under the same pressure, a volume adder for providing a known volume variation to either one of the container to be measured and the reference container, and a differential pressure detector for measuring the differential pressure between the container to be measured and the reference container. The ratio of the differential pressure variation to the volume variation, which represents the sensitivity for detecting differential pressure, is precalculated based on differential pressure variations obtained in the cases where the volume variation is provided and is not provided.

Abstract: Leak test equipment which includes a master side pneumatic system and a work side pneumatic system executes a leakage test sequence basically including pressurizing, balancing and detecting steps under control of a microcomputer. A nonvolatile read/write memory has prestored therein an equivalent inner volume of the work side pneumatic system corresponding to each type of work being tested for leakage. In a leak test, a leakage .DELTA.V.sub.L =V.sub.E .multidot..DELTA.P/1.03 is calculated on the basis of a pressure difference .DELTA.P between the work side pneumatic system and the master side pneumatic system, detected in the detecting step, and a corresponding equivalent inner volume V.sub.E read out of the nonvolatile read/write memory. The calculated leakage is compared with an allowable value of leakage, thereby deciding whether the work is acceptable or not.

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.

Abstract: A predetermined number of preceding data items, which are obtained through measurement of change in pressure or pressure difference with respect to respective objects inspected and decided to be acceptable, are grouped according to types of the objects and stored in different storage regions. Each time new data is stored, the oldest data in the corresponding storage region is erased. An average of data stored in a designated storage region is computed and each object is decided if it is acceptable or not on the basis of the difference between the newly measured data of the object and the computed average of the data in the designated storage region corresponding to the object.

Abstract: In a device in which a positive or negative pneumatic pressure source is coupled with a controlled system through a first electromagnetic valve and the controlled system is coupled with a negative or positive pneumatic pressure source through a second electromagnetic valve or opened therethrough to the air, and which is adapted so that the first and second electromagnetic valves are controlled to open or close to thereby set an air pressure in the controlled system, a deviation between the pressure of the controlled system and the set pressure is detected and the detected deviation signal is converted by a pulse converter into a pulse of the duty ratio or frequency corresponding to the deviation, by which pulse the first and second electromagnetic valves are controlled to open or close.