Patent ID: 7990161

Claim:
An apparatus for measuring the total acid number of lubricant and insulating oils, the apparatus comprising: a unit for storing a total acid number table in which a change in conductance and the corresponding measurement values of total acid number and physical properties of oils are matched; a unit for measuring conductance in the oils; and a total acid number-determining unit for searching the total acid number table to determine the total acid number and physical properties according to the determined conductance and outputting the determined total acid number or physical properties of oils, or information about the determined total acid number or physical properties, the total acid number-determining unit communicatively coupled with the unit for storing a total acid number table and the unit for measuring conductance, the unit for measuring conductance including a substrate formed to have a given area, a plate-shaped conductance sensing film for measuring the conductance of oils in which the sensing film has a plurality of holes formed therein and is formed by screen-printing carbon nanotubes on the upper surface of the substrate and sintering the printed carbon nanotubes, and a vacuum deposited overlying electrode pattern extending on the upper surface of the sensing film or extending from the upper surface of the sensing film to the upper surface of the substrate connected to an external power source.