To provide a sensor for detecting an acidity/basicity which can prevent short circuits brought about by the adhesion of metal powders or conductive reactants having a length, whereby the powders or reactants can stride across a pair of electrodes changing the potential different in response to an acidity/ basicity in an oil.
A partition film 23 of an insulating material is set between the electrodes of an electrode pair structure 20 in the comb-teeth shape changing the potential different in response to the acidity/basicity, i.e., between different electrodes 21a and 22a. The metal powders or conductive reactants having the length, by which the metal powders or conductive reactants can stride across the electrodes 21a and 22a are prevented from adhering to bridge the electrodes 21a and 22a. Even if metal powders or conductive reactants which turn into a factor of abnormal detected values are included in the oil, a stable sensor output performance can be obtained.
YOSHIDA TAKAHIKO
YORINAGA MUNEO
HORIE KAZUYUKI
UEDA KOJI
NAITO KIWAMU
DENSO CORP