Patent ID: 7391225
Filing Date: 2008-06-24
Classification: G01N,G01R

Abstract:
1. An apparatus for determining a time to change automobile engine oil, comprising: a power source unit for converting power, which is supplied from a battery, into necessary power and supplying the necessary power at a startup time; a degradation detection unit installed in an engine oil chamber and formed using carbon nanotubes as a sensor capable of detecting degradation of the engine oil; a drive unit for driving operation of the degradation detection unit when enabled by power supplied from the power source unit; a small signal amplification unit for amplifying a minute signal output from the degradation detection unit; an oil-condition determination unit for comparing a value, corresponding to the degraded state of the engine oil, with a set reference values based on a detection signal transferred from the small signal amplification unit, and thereby determining a time to change the engine oil; an amplification unit for amplifying a signal detected by the oil-condition determination unit to a preset level; and a display unit for displaying a signal, which is output from the oil-condition determination unit, in text or predetermined form as information about an oil change time; wherein the sensor of the degradation detection unit is an electric conductivity sensor, the electric conductivity sensor comprising: electrodes to which power is applied; a detection film which is connected to both the electrodes and is formed of carbon nanotubes capable of detecting variation in permittivity; and a substrate on which the electrodes and the detection film are mounted.