Patent attributes
A flow sensor readily obtains high sensitivity without errors due to tilting. The flow sensor includes a flow channel having a pair of parallel portions and temperature sensing resistors for heating a fluid to a preset temperature. The temperature sensing resistors are disposed on parts of the parallel portions of the flow channel, to detect a fluid flow rate based on a change in temperature distribution of a flow channel due to a change in flow rate of the fluid flowing through the flow channel. The temperature sensing resistors include a first upstream temperature sensing resistor and a first downstream temperature sensing resistor that are disposed in a line on upstream and downstream sides of one of the parallel portions, respectively; and a second upstream temperature sensing resistor and a second downstream temperature sensing resistor that are disposed in a line on upstream and downstream sides of the other parallel portion, respectively.
