A flow rate sensor includes: a housing made from a resin material and having a bottom base portion and a side wall, at least one surface side of the housing being open; a cover made from a resin material, covering the one surface side of the housing, welded to an upper surface of the side wall of the housing, and defining, with the bottom base portion and the side wall of the housing, an auxiliary passage within which a gas to be measured flows that is taken in from a main passage; and a flow rate detection unit disposed within the auxiliary passage. A protruding portion for height control is provided to one of the housing and the cover at least in a vicinity of the side wall around the flow rate detection unit so as to suppress sinking in of the cover during welding.

The present invention provides a thermal flowmeter having good measurement accuracy by reducing deviation in the flow velocity distribution of a gas under measurement flowing through an auxiliary passage. An auxiliary passage 330 for taking in a portion of a gas under measurement IA flowing through a main passage 124 has a curved passage 32a that bends toward a flowrate measurement element 602. The curved passage 32a has a resistance portion 50 formed therein that applies resistance to the flow of the gas under measurement IA flowing through the outer peripheral side CO of the curved passage 32a so that the pressure loss of the gas under measurement IA flowing through the outer peripheral side CO is high compared to that of the gas flowing through the inner peripheral side CI of the curved passage 32a.

A connection terminal is on a flange of a thermal flow meter. A terminal connection part has a first and a second bent part. The first bent part is bent from a first direction to a second direction. The second bent part has is bent from the first bent part to a third direction. The first and second bent parts are formed such that when connection pin parts of a plurality of the connection terminals and terminal connection parts of the plurality of connection terminals are projected onto a first imaginary plane, an imaginary line L extending along a first direction passing through the projection areas of each of the terminal connection parts of the plurality of connection terminals passes between the projection areas of the connection pin parts from among the connection pin parts of the plurality of connection terminals, that are positioned on both sides.

A system for metering gas includes a flow sensor and a controller. The flow sensor is disposed in a conduit in fluid connection with a flow of a gas through the conduit. The flow sensor includes a heater and a temperature sensing element, and generates an electrical output based on the flow of the gas. The controller controls operation of the heater and is operable in a pre-measurement mode and multiple measurement modes. The controller in the pre-measurement mode operates the heater at a pre-measurement setting. The controller in the measurement modes operates the heater at corresponding measurement settings that have increased power levels and/or increased operating durations relative to the pre-measurement setting. The controller in the measurement modes is configured to determine a flow rate of the gas based on an amplitude characteristic and/or a temporal characteristic of the electrical output of the flow sensor.

The purpose of this invention obtain a physical-quantity detection device, the external shape of the housing of which can be reduced in size. Said physical-quantity detection device, which detects a plurality of physical quantities of a gas being measured that flows through a main channel, is characterized by having a housing positioned inside said main channel, a circuit board insert-molded into said housing, and a plurality of detection sensors mounted on both sides of the circuit board.

The present invention provides a thermal flow meter 300 which reduces a stress applied from a fixing portion 3721, which is used to hold and fix a circuit package 400 with respect to a housing 302, to the circuit package 400 and has high reliability. In the thermal flow meter of the invention, the circuit package 400 embedded with a flow rate measurement circuit is formed through a first resin molding process, the fixing portion 3721 is formed along with the housing 302 through a second resin molding process, and the circuit package 400 is enveloped by the fixing portion 3721, whereby the circuit package 400 is held by and fixed to the housing 302. In order to reduce the influence of a stress, generated based on a temperature change of the fixing portion 3721, on the circuit package 400, the fixing portion 3721 is constituted of a thick portion 4714 and a thin portion 4710. Since thickness of a resin of the thin portion 4710 is small, the stress to be generated is small, and a force applied to the circuit package 400 can be reduced.

The present invention provides a thermal flow meter 300 which reduces a stress applied from a fixing portion 3721, which is used to hold and fix a circuit package 400 with respect to a housing 302, to the circuit package 400 and has high reliability. In the thermal flow meter of the invention, the circuit package 400 embedded with a flow rate measurement circuit is formed through a first resin molding process, the fixing portion 3721 is formed along with the housing 302 through a second resin molding process, and the circuit package 400 is enveloped by the fixing portion 3721, whereby the circuit package 400 is held by and fixed to the housing 302. In order to reduce the influence of a stress, generated based on a temperature change of the fixing portion 3721, on the circuit package 400, the fixing portion 3721 is constituted of a thick portion 4714 and a thin portion 4710. Since thickness of a resin of the thin portion 4710 is small, the stress to be generated is small, and a force applied to the circuit package 400 can be reduced.

A physical quantity detector includes a housing, a circuit board, a cover, a resin member, a conductor, and a conductive member. The circuit board includes a board surface. The cover faces the board surface and defines, together with the hosing, a passage through which the target fluid flows. The conductor includes a passage side portion and a connecting portion. The conductive member electrically connects the connecting portion to the circuit board. The conductive member includes a first end in the thickness direction facing a contact target that is either one of the connecting portion or the board surface. The first end includes a contact portion in contact with the contact target and a contactless portion away from the contact target in the thickness direction.

The disclosed embodiments include a method, apparatus, and computer program product for providing a self-validating mass flow controller or mass flow meter. For example, in one embodiment, a self-validating mass flow controller is disclosed that does not require any software modification to a tool/tool controller in which the mass flow controller is being utilized. In other embodiments, a self-validating mass flow controller is disclosed that does not require any hardware or mechanical changes to an existing mass flow controller. Still, the disclosed embodiments further include a self-validating mass flow controller that is configured to determine valve leak and sensor offset simultaneously for performing real time in-situ correction of a mass flow controller's output for zero offset or zero drift in the presence of valve leak.

The disclosed embodiments include a method, apparatus, and computer program product for providing a self-validating mass flow controller or mass flow meter. For example, in one embodiment, a self-validating mass flow controller is disclosed that does not require any software modification to a tool/tool controller in which the mass flow controller is being utilized. In other embodiments, a self-validating mass flow controller is disclosed that does not require any hardware or mechanical changes to an existing mass flow controller. Still, the disclosed embodiments further include a self-validating mass flow controller that is configured to determine valve leak and sensor offset simultaneously for performing real time in-situ correction of a mass flow controller's output for zero offset or zero drift in the presence of valve leak.