公开(公告)号：US12264949B2

公开(公告)日：2025-04-01

申请号：US17764304

申请日：2020-10-16

Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY ,  FUKUDA CO., LTD.

Inventor： Hajime Yoshida ,  Yoshinori Takei ,  Kenta Arai ,  Mao Hirata ,  Tsutomu Hara ,  Jun Inomata

IPC: G06F11/30 ,  G01F1/34 ,  G01M3/28 ,  G06F113/08

Abstract: A flow rate of a gas is determined based on a predetermined relational expression including, as parameters: the flow rate of the gas; diameter and length of a hole; upstream and downstream pressures; and temperature, molecular weight, viscosity coefficient, and specific heat ratio of the gas. Additionally, setting conditions for a type and temperature of the gas, the length of the hole, and the pressures upstream and downstream from the hole are set; the relational expression is used to obtain the correspondence relationship between the diameter of the hole and the flow rate of the gas flowing through the hole; an approximation function approximating the obtained correspondence relationship is determined; the flow rate of a gas passing through a test piece having a hole of an unknown diameter is measured; and the diameter of the hole is estimated, based on the measured flow rate and the approximation function.

公开(公告)号：US10254189B2

公开(公告)日：2019-04-09

申请号：US15723752

申请日：2017-10-03

Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY

Inventor： Hajime Yoshida ,  Kenta Arai ,  Tokihiko Kobata

IPC: G01M3/00 ,  G01M3/20 ,  G01M3/26 ,  G01L27/00 ,  B81B7/00

Abstract: A static expansion method is performed by expanding a volume of a testing gas from V0 to V0+V1 between a second chamber of the volume V1 which is connected to an upstream side of a measurement chamber and a first chamber of the volume V0 which is connected to an upstream side of the second chamber, wherein the first camber is in communication with the second chamber via a first valve, wherein the second chamber is in communication with the measurement chamber via each of a second valve and an orifice or porous plug, respectively. When the first valve is opened and the second valve is closed, the testing gas flows from the first chamber via the second chamber into the measurement chamber only through the orifice or porous plug.