Thermal Flow Meter

摘要

In order to provide a thermal flow meter (300) for improving workability of a flow rate measurement device having a temperature measurement function for the measurement target gas (30) and measurement accuracy for measuring a temperature, the thermal flow meter is structured such that a flow rate measurement circuit package (400) having a protrusion (424) for measuring a gas temperature is formed through resin molding, an inlet port (343) opened to the upstream side of the measurement target gas (30) is formed, a protrusion (424) is arranged inside the inlet port, an inlet port (344) and an outlet port (345) are formed in the front and rear covers (303 and 304) along the protrusion (424), and the measurement target gas (30) received from the inlet port (343) flows along the protrusion (424). Since the measurement target gas (30) subjected to the measurement flows along the protrusion (424), it is possible to reduce influence of the heat from other heat resources and improve measurement accuracy.

主权项

1. A thermal flow meter having a bypass passage for receiving and flowing a part of a measurement target gas flowing through a main passage, a circuit package that measures a flow rate by performing heat transfer with the measurement target gas flowing through the bypass passage and measures a temperature of the measurement target gas flowing through the main passage, a housing that holds the circuit package, and covers that cover the housing,
wherein the circuit package has a protrusion having a temperature detection element for detecting a temperature of the measurement target gas, the covers that cover the housing are arranged in side portions of the protrusion, so that an inlet port for receiving the measurement target gas is formed in a leading end side of the protrusion, and the cover is provided with an opening for discharging, to the main passage, the measurement target gas that is received from the inlet port and flows along the protrusion.