| 摘要 |
PROBLEM TO BE SOLVED: To improve measurement precision of an actual gas flow rate by improving linearity of flow rate output characteristics.SOLUTION: A thermal flow sensor includes a main flow passage 2 where a fluid flows and a sensor flow passage 3 branching off from the main flow passage 2 and provided with a flow rate detecting mechanism 4 which detects the flow rate of a fluid by shunting the fluid. The flow rate detecting mechanism 4 includes an upstream coil 411 and a downstream coil 412 formed of heating resistance wires wound around a sensor flow passage tube 300 forming the sensor flow passage 3, a peak position of a temperature distribution generated in the sensor flow passage 3 by the upstream coil 411 and downstream coil 412 being more on the side of the upstream coil 411 than the center position X of the sensor flow passage 3 between the upstream coil 411 and downstream coil 412. |
