| 摘要 |
PROBLEM TO BE SOLVED: To determine a deterioration of an oil itself accompanied by a change in pH by directly immersing a pH electrode into a sample oil, and as a result, to enable a deterioration state of the oil such as a lubricating oil to be continuously detected on line.SOLUTION: A ph semiconductor sensor manufactured by using a glass electrode or an ISFET (Ion-Sensitive Field-Effect Transistor) structure directly immerses a pH sensor part, which is formed by coating a non-oil-soluble and electrically-conductive ion liquid film 15 on an outer surface of a sensor support body between a liquid junction part 23 at the side of a comparison electrode 20 serving as an active area and a pH responsive glass thin film 12 (or an ISFET electrode 10b), into an oil and determines a deterioration of the oil itself accompanying a change in pH. Preferably, a thickening agent is contained in a range of 1 to 50 mass% with respect to an ionic liquid 15. |
