Patent ID: 8181513

Claim:
A flow meter comprising: a body portion containing a main flow path wherein a fluid to be measured flows; a first branch flow path branching the flow of the fluid to be measured from the main flow path; a second branch flow path causing the fluid to be measured, for which the flow has been branched, to flow back into the main flow path from the first branch flow path; a narrow portion for narrowing the flow of the fluid to be measured, provided between the first and second branch flow paths; and a fluid measuring portion having: a branched flow path structuring portion that is provided with a flow path for carrying the fluid to be measured, connected to the first and second branch flow paths; and a sensor disposed facing the flow path provided in the branched flow path structuring portion, measuring the fluid to be measured based on a detection result for the fluid to be measured that has been introduced from the branch flow path, detected by the sensor; wherein the fluid measuring portion is detachably attached to the body portion.