PURPOSE: To detect a deterioration of oil by dipping part of a metallic resistor in the oil and detecting variation in resistance value.
CONSTITUTION: An oil deterioration detecting element 1 consists of a substrate 13 and the metallic resistor 11. The substrate 13 is made of an insulator such as alumina and the metallic resistor 11 is formed thereupon by vacuum deposition, plating, etc. The resistor 11 is made of metal such as iron, copper and the element 1 is adhered to a housing 31 with a sealant 32 such as epoxy resin, and a protection cover 33 having a small hole 331 is provided atop of the housing 31 so as to prevent the element 1 from being broken. Then part of the resistor 11 is dipped in the oil and the resistor 11 on the substrate 13 corrodes owing to the deterioration of the oil, i.e. an increase in total acid number; and variation in resistance value is detected by a detection part 4 and displayed on a display part 5. Thus, the deterioration of the oil is detected.
HATTORI TADASHI
ATSUMI KINYA
