Abstract:A multi parameter measurement sensor for hydraulic oil pollutants is proposed. Based on the planar microfluidic inductance sensor, a single layer inductance coil is added in the sensor. Two singlelayer coils are arranged on both sides of the straight microchannel. On the basis of inductance parameter detection, the two singlelayer inductor coils are equivalent to a pair of ring shaped capacitor plates, the capacitance parameter detection is introduced, and the multiparameter sensor achieves the detection of four pollutants (ferromagnetic metal particles, nonferromagnetic metal particles, water droplets and air bubbles) in the hydraulic oil. The design of multiparameter sensor was carried out, and the detection position was optimized through simulation and experiments. The capacitance parameter detection experiment realizes the differential detection of 180 μm water droplets and 240 μm air bubbles; and the inductance parameter detection experiment realizes the differential detection of 80 μm iron particles and 150 μm copper particles in hydraulic oil, respectively. The study provides a new approach for the differential detection of multipollutants in hydraulic oil.