Fluid quality sensor

摘要

An object of the present invention is to accurately detect concentrations of mixtures in a fluid. An internal electrode 23 is disposed on the inner side of an external electrode 22 coaxially with the external electrode 22, and a plurality of points in the length direction of the internal electrode 23 are supported by a casing 21 via supporting members 28a and 28b. The state of a fluid S passing through a passage 26 between the external electrode 22 and the internal electrode 23 is detected based on electrostatic capacitance between the external electrode 22 and the internal electrode 23.

主权项

1. A fluid quality sensor for measuring mixture fluid comprising:
a tubular casing having a first end and a second end and extending in an axial direction from the first end to the second end; a tubular external electrode disposed in an interior space defined by the tubular casing; an internal electrode disposed in an interior space defined by the external electrode, the internal electrode being positioned apart from and coaxially with the external electrode, a first passage being formed between an inner surface of the external electrode and an outer surface of the internal electrode; a pair of first members engaged with the external electrode in the axial direction, each of the first members including an electrical insulator; a pair of second members engaged with the pair of the first members, respectively, in the axial direction, each of the second members including at least one hole extending in a radial direction through the respective second member; each of the second members being engaged with an inner surface of the tubular casing in a radial direction, thereby preventing the second members from moving in the radial direction relative to the tubular casing, each of the second members including an electrical conductor; at least one supporting member connecting a surface of the at least one hole defined in each of the second members and the outer surface of the internal electrode, the at least one support member including an electrical conductor; an annular intake part engaged with the first end of the tubular casing in the axial direction, a second passage being formed in the annular intake part; and an annular outlet part engaged with the second end of the tubular casing in the axial direction, a third passage being formed in the annular outlet part, wherein concentration of a fluid passing from the second passage through the first passage to the third passage is detected based on electrostatic capacitance between the external electrode and the internal electrode.