Capacitance electrode structure for measuring moisture

摘要

Device (1) for measuring moisture of materials flowing in the shape of dried, liquid or gaseous granulates, or in the shape of powders in at least one duct disposed at least partially along an axis (X-X) through which the material of which the moisture has to be measured flows, comprising: at least one capacitor (Cx) wherein the material of which the moisture has to be measured flows, characterized in that the capacitor (CX) comprises: at least two metallic rings (3) coaxially mounted to said axis X-X and adjacent to an inner wall of the duct through which the material of which the moisture has to be measured flows; at least one dielectric element (5) having: dielectric constant substantially linear with the temperature changing, and thermal expansion lower than α=27×10−6/° C.

主权项

1. Device (1) for measuring moisture of materials flowing in the shape of dried, liquid or gaseous granulates, or in the shape of powders in at least one duct disposed at least partially along the axis (X-X) through which the material of which the moisture has to be measured flows, comprising: at least one capacitor (Cx) having a hollow cylindrical shape through which the material of which the moisture has to be measured flows, characterized in that the capacitor (CX) comprises: at least two metallic rings (3) coaxially mounted to said axis (X-X) and adjacent to an inner wall of the duct through which the material of which the moisture has to be measured flows; at least one dielectric element (5) and a second dielectric element (5), each having: dielectric constant substantially linear with the temperature changing, and thermal expansion lower than α=27 ×10−6/° C.; said at least one dielectric element (5) and said second dielectric element (5) each comprising a ring (6) of dielectric material having an annular inner seat (7) adapted for housing at least partially one of said metallic rings (3); said annular seats (7) of said two rings (6) of dielectric material adjacent in direction of said axis (X-X))substantially housing completely said one of said metallic rings (3), hermetically sealing inner walls of said capacitor (Cx); and said two rings (6) of dielectric material adjacent in direction of said axis (X-X) and said one of said metallic rings (3), forming a modular structure allowing said one of said metallic rings (3) and said two rings (6) of dielectric material to he added to adapt the measuring device (1) to different ducts.