ADJUSTMENT DEVICE FOR FLOW RATE SENSOR

PROBLEM TO BE SOLVED: To provide an adjustment device for a flow rate sensor that can easily achieve the rotation adjustment work for an impeller without using a dedicated controller. SOLUTION: A water meter 1 comprises a fluid pipe 2, an impeller 3 arranged inside this fluid pipe 2, and a flow straightener 4 arranged at the upper stream side of the impeller 3. The rotation adjustment for the impeller 3 is achieved by relatively rotating the flow straightener 4 to the fluid pipe 2 circumferentially. A fitting projection 441 and a fitting groove 261 are formed on an annular end surface 44 and a circular step surface 26 which are the matching surfaces of the flow straightener 4 and the fluid pipe 2, and thereby a relative circumferential position is defined. A projection 46 formed on the outer circumference surface of the flow straightener 4 is fitted into a circular groove 25 formed on the internal circumference surface of the fluid pipe 2, and thereby the flow straightener 4 is fixed at a rotation position after adjustment in the fluid pipe 2.