Patent ID: 7182847

Claim:
A probe for determining a pH level of a sample medium, the probe comprising: a flexible outer tube having a flexible inner tube concentrically arranged therein, wherein a lumen of the inner tube comprises a pH-sensitive electrode having a conducting portion and a sensing portion, which protrudes from a first end of the inner tube for detecting a signal used to determine the pH level of the sample medium, wherein: the conducting portion comprises one or more antimony rods; and the sensing portion comprises a smooth hemispherical tip formed by dipping one end of the antimony rods into liquefied antimony and allowing the sensing portion to harden while pointing in a downward direction; wherein a space between the inner tube and the outer tube comprises: a reference electrode configured to fill at least a portion of the space; a temperature electrode arranged along one side of the space; and wherein a sidewall of the outer tube comprises one or more diffusion windows located proximate to a first end of the outer tube to provide electrical coupling between the reference electrode and the sample medium.