A pressure control device includes a pressure control valve, a flow resistance provided downstream of the pressure control valve, a first pressure sensor for measuring a gas pressure between the pressure control valve and the flow resistance, a second pressure sensor for measuring a gas pressure downstream of the flow resistance, and a calculation control circuit connected to the first pressure sensor and the second pressure sensor, wherein the pressure control device controls the gas pressure downstream of the flow resistance by adjusting an opening degree of the pressure control valve based on an output of the second pressure sensor regardless of an output of the first pressure sensor control, and calculates the flow rate of the gas downstream of the flow resistance, based on the outputs of the first and the second pressure sensors.

It is intended to provide a measuring instrument or the like capable of measuring a flow property of a small amount of sample. A measuring instrument 101 configured to measure a flow property of a test liquid 5, the measuring instrument 101 including: a push-back means configured to push back the test liquid 5, the test liquid 5 having flowed into a capillary tube 11 including a first opening part 111 and a second opening part 112 from the second opening part 112 side toward the first opening part 111 side, to the second opening part 112 side; an adjustment valve for adjusting liquid flow in the capillary tube 11; and a measurement unit 6 configured to measure an arrival time tn at a liquid level position Ln in the capillary tube 11.

It is intended to provide a measuring instrument or the like capable of measuring a flow property of a small amount of sample. A measuring instrument 101 configured to measure a flow property of a test liquid 5, the measuring instrument 101 including: a push-back means configured to push back the test liquid 5, the test liquid 5 having flowed into a capillary tube 11 including a first opening part 111 and a second opening part 112 from the second opening part 112 side toward the first opening part 111 side, to the second opening part 112 side; an adjustment valve for adjusting liquid flow in the capillary tube 11; and a measurement unit 6 configured to measure an arrival time tn at a liquid level position Ln in the capillary tube 11.

Various methods, apparatuses, and systems for improving sensitivity and performance of a flow sensing apparatus are provided. The flow sensing apparatus includes: a housing defining an inlet port and an outlet port; a sensing element disposed at least partially within the housing; a main flow path defined within the housing connecting the inlet port and the outlet port, where the main flow path is disposed proximate the sensing element such that at least a portion of the flowing media is in fluid contact with the sensing element; and a laminarizing structure located in the inlet port and configured to direct a flowing media in a laminar flow pattern.

Various methods, apparatuses, and systems for improving sensitivity and performance of a flow sensing apparatus are provided. The flow sensing apparatus includes: a housing defining an inlet port and an outlet port; a sensing element disposed at least partially within the housing; a main flow path defined within the housing connecting the inlet port and the outlet port, where the main flow path is disposed proximate the sensing element such that at least a portion of the flowing media is in fluid contact with the sensing element; and a laminarizing structure located in the inlet port and configured to direct a flowing media in a laminar flow pattern.