Real-Time Monitoring of Hydraulic Oil Deterioration Using a Hall Effect Sensor Under Operational Conditions

This paper presents a method for measuring hydraulic oil degradation by detecting metal particle flow using a permanent magnet's magnetic field and monitoring voltage changes in a Hall effect sensor (HES). Degraded hydraulic oil containing increased metal contaminants from component wear exhibits reduced viscosity and higher flow rates. We developed a measurement device incorporating a microcontroller to process data and display contamination levels on an organic light-emitting diode (OLED) screen, enabling real-time monitoring without interrupting machine operations. Experiments measured voltage variations at three system locations with metal contamination levels from 2.5 to 5.0 grams per liter (in 0.5 grams per liter increments). Results showed the HES output voltage varied linearly with particle concentration, demonstrating a maximum deviation of 4.73 millivolts (0.47 %) at 2.5 grams per liter, particularly at the reservoir outlet. This approach helps assess hydraulic oil contamination under operational conditions, offering advantages in real-time monitoring capability, cost-effectiveness, and non-invasive implementation.