Azbil Corporation

Yamatake Corporation

Masaki Seo

Junichi Matsuda

Manabu Muraoka

Masanori Anzai

Yasuharu Ooishi

Koichiro Niikawa

A thermal flow meter has a sensor chip, a heater, first and second flow rate calculators, and an output controller. The heater increases the ambient temperature in the vicinity of a pair of temperature-sensing elements on the sensor chip by a particular temperature above a temperature of a fluid flowing along the sensor chip. The first flow rate calculator calculates a flow rate of the fluid from a temperature difference detected by the pair of temperature-sensing elements. The second flow rate calculator calculates a flow rate of the fluid from a driving energy of the heater. The output controller outputs the flow rate calculated by the second flow rate calculator, instead of the flow rate calculated by the first flow rate calculator, when the flow rate calculated by the first flow rate calculator exceeds a flow rate threshold value that is set in advance.

Thermal flow meter measuring flow rate based on temperature difference measurement and driving energy of the heater

A flow meter includes: a body portion comprising a main flow path wherein flows a fluid to be measured, a first branch flow portion wherein the fluid to be measured branches and flows from the main flow path, a second branch flow portion wherein the fluid to be measured, which branches and flows from the first branch flow portion, flows into the main flow path, and narrow portions for restricting the flow of the fluid to be measured, provided in a primary flow path between the branch flow portions, a branched flow path structuring portion through which flows the fluid to be measured, connected to the branch flow portions; and a fluid measuring portion provided with a sensor disposed facing a flow path that is provided in the branched flow path structuring portion, wherein the sensor measures the fluid based on the detection results of the fluid introduced from the branch flow portions.

Flow meter

The flow meter is equipped with first and second flow paths, provided in parallel and through which flows fluid having flowed through and being diverted from a main flow path, the flow diversion ratio among the first and second flow paths changing passively in accordance with the flow rate of fluid through the main flow path, and a flow rate sensor provided on at least one of the first and second flow paths. The first and second flow paths are formed, for example, as flow paths having different flow path cross-sectional areas, or alternatively are formed from mesh elements provided with mesh-free areas on a portion thereof. Alternatively, one of the either the first or second flow path is realized with a paddle mechanism incorporated therein.

Growing community of inventors

Tokyo, Japan

Masaki Seo