Research On Interface Detection Technology Based On The Induced Current Method

With the improvement of science and technology, the detection of the interface position and related parameters, such as the zeta potential, play an important role in ships, machinery, biology, chemistry, and many other fields such as environmental pollutants detection. At present, there are many different methods of detection technology, but development of new and more convenient detection technology is still of great significance in allusion to a specific and broader application.A kind of interface detection method based on the principle of induced current is presented. By analyzing the characteristics of interface and building the differential signal amplification system, the position of oil-water interface is detected, and the zeta potential of the gas-liquid interface and the solid-liquid interface is measured. The related research tasks are listed as follows:(1) Based on the induced current method, the position of oil-water interface is detected and the composition of the oil is distinguished. The results indicate that based on the time when the voltage signal appears and the descent rate of the detecting electrode during detection, the position of oil-water interface is known quickly. According to the different signals when the detection electrodes respectively contact diesel oil-ultrapure water interface, lubricating oil-ultrapure water interface, diesel oil-seawater interface and lubricating oil-seawater interface, the different oil dielectric property is achieved.(2) The zeta potential of gas-liquid interface is measured. The results show that the position of air-liquid interface and the corresponding zeta potential is obtained accurately, and the results show no dependence on the types and concentrations of the solution.(3) The zeta potential at the PDMS surface in micro-channel is detected. The results show that based on the self-designed micro-channel, the zeta potential of PDMS-liquid interface is measured rapidly and accurately. What’s more, by changing the thickness of PDMS and the resistance of the resistor, the detection sensitivity of this system could be improved. Then, a foundation is laid for the further study of a series of electro-kinetic phenomena inside the microfluidic chip.A new interface detection technology based on induced current method is this method can be used to develop a novel and portable interface detection device.