Abstract: A pH sensor for detecting a pH of a sample includes a reference electrode and a glass electrode. The reference electrode includes a hollow tubular housing, and at least one water absorbing unit disposed in the housing and including a porous junction member configured to contact the sample, and a water absorbing member disposed on one side of the porous junction member that is opposite to the sample. The water absorbing member is made by soaking a superabsorbent polymer in potassium chloride solution. The glass electrode is inserted into the water absorbing member, and protrudes from the junction member toward the sample.

Abstract: A pH sensor for detecting a pH of a sample includes a reference electrode and a glass electrode. The reference electrode includes a hollow tubular housing, and at least one water absorbing unit disposed in the housing and including a porous junction member configured to contact the sample, and a water absorbing member disposed on one side of the porous junction member that is opposite to the sample. The water absorbing member is made by soaking a superabsorbent polymer in potassium chloride solution. The glass electrode is inserted into the water absorbing member, and protrudes from the junction member toward the sample.

Abstract: A variable pressure reducing device includes a hollow housing body formed with an inlet opening, an outlet opening spaced apart from the inlet opening, and an inner wall surface. The variable pressure reducing device further includes an intake tube that extends into the housing body from the inlet opening. The intake tube is formed with an inlet channel and is further formed with an outer tube surface that cooperates with the inner wall surface to form an outlet channel in fluid communication with the outlet opening. The variable pressure reducing device also includes a redirection structure movably mounted in the housing body and movable relative to the intake tube between a redirecting state and a sealing state.