Thermal flow meter with temperature detection element positioned on protrusion of circuit package

A thermal flow meter comprising:

• 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 on opposite sides of the protrusion forming an inlet port at a leading end of the protrusion for receiving the measurement target gas,
• at least one of the covers 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,
• the circuit package that measures the flow rate has a circuit package body, and the protrusion that has the temperature detection element protrudes from the circuit package body,
• the circuit package body is held inside the housing, and
• the protrusion protrudes from the housing toward an upstream direction of the main passage.

A thermal flow meter comprising:

• 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 on opposite sides of the protrusion forming an inlet port at a leading end of the protrusion for receiving the measurement target gas,
• at least one of the covers 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,
• the housing has an external terminal for connection with external devices, a first housing portion in an external terminal side, and a second housing portion in a bypass passage side,
• a temperature measurement flow path for flowing the measurement target gas that detects a temperature is arranged between the first and second housing portions,
• the inlet port for receiving the measurement target gas is formed in an upstream side in the main passage of the temperature measurement flow path, and
• the protrusion is arranged in the temperature measurement flow path.