An Oil Multipollutant Detection Sensor With High Sensitivity and High Throughput

Oil is rich in information about the operating status of machinery and equipment, and oil condition monitoring is essential for maintaining the safety and reliability of machinery and equipment. Most sensors not only have the problem of small detection throughput and low detection efficiency, but also large-sized contaminants can easily block or even scratch the detection channel. A sensor with high sensitivity and high throughput for detecting multiple oil contamination is designed in this article. The sensor comprises four glass capillary detection channels and four detection units, including a planar coil, solenoid coil, cylindrical parallel plate capacitor, and rectangular parallel plate capacitor. Detection flux of the sensor is increased by 12 times its initial value, which significantly improves the detection efficiency. Through experimental research, in the inductance mode, the best excitation frequency is 2 MHz, and the voltage is 2 V. In the capacitance mode, the best excitation frequency is 1.8 MHz, and the voltage is 2 V. In addition, the sensor has a higher detection capability for Fe than Cu in the inductance mode, and a higher detection capability for water droplets than air bubbles in the capacitance mode. By analyzing the signal characteristics of each sensor unit, the sensor can distinguish between Fe of 38–
$900 ~\mu \text{m}$
and Cu of 88–
$900 ~\mu \text{m}$
, as well as water droplets greater than
$130 ~\mu \text{m}$
and air bubbles greater than
$100 ~\mu \text{m}$
. This research provides a new idea for online oil monitoring.