Patent ID: 7878072

Claim:
A measurement device comprising: a container in which a measurement target flows or is sealed, the container including an aperture; a lining which is applied to an inner surface of the container; an electrode provided in the aperture; a sealing member; and a spring configured to bias the electrode in a direction from the inside to the outside of the container; wherein the electrode includes: an electrode head provided with a first surface, which is exposed to the inside of the container and is in contact with the measurement target, and a second surface located on an opposite side to the first surface; an anchor formed on an outer peripheral portion of the electrode head so as to protrude from the second surface and to be buried in the lining; an electrode shaft formed integrally with the electrode head so as to extend toward the opposite side of the first surface; and an electrode tapered portion tapered with its diameter gradually reduced from the anchor to the electrode shaft so as to fit in the aperture; and wherein the electrode is inserted from the inside of the container so as to expose a part of the electrode shaft out of the container, wherein the aperture is formed with a first tapered portion and a second tapered portion, the first tapered portion is tapered from an outer surface of the container with its diameter gradually reduced from the outer surface to the inner surface of the container, and the second tapered portion is tapered from an inner surface of the container with its diameter gradually reduced from the inner surface to an outer surface of the container, and wherein the sealing member is fitted to the first tapered portion on the aperture and is biased from the outside to the inside of the container by the spring.