Thermal Flow Meter

摘要

Provided is a thermal flow meter to improve the measurement accuracy of a temperature detector provided in a thermal flow meter. The thermal flow meter includes a bypass passage through which a measurement target gas 30 flowing through a main passage flows, and a circuit package 400 which includes a measurement circuit for measuring a flow rate of the measurement target gas 30 flowing through the bypass passage and a temperature detecting portion 452 for detecting a temperature of the measurement target gas. The circuit package 400 includes a circuit package body which is molded by a resin to internally envelope the measurement circuit and a protrusion 424 molded by the resin. The temperature detecting portion 452 is provided in the leading end portion of the protrusion 424, and at least the leading end portion of the protrusion protrudes to the outside from a housing 302.

主权项

1. A thermal flow meter comprising:
a bypass passage into which a measurement target gas flowing through a main passage flows; a circuit package which includes a measurement circuit for measuring a flow rate by performing heat transfer with the measurement target gas flowing through the bypass passage and a temperature detecting portion for detecting a temperature of the measurement target gas; and a case which includes an external terminal for outputting an electric signal representing the flow rate and an electric signal representing a temperature of the measurement target gas and supports the circuit package, wherein the case includes a resin housing which supports the circuit package, the circuit package is configured to envelope the measurement circuit and the temperature detecting portion with a resin, the temperature detecting portion includes a protrusion protruding from a circuit package body, and at least a leading end portion of the protrusion is exposed in the main passage.