Non-contact electromagnetic detection method for discrete phase non-conductive particles

Abstract

The invention discloses a non-contact electromagnetic detection method for discrete phase non-conductive particles, which belongs to the field of electromagnetic measurement. The method specifically comprises the steps of firstly, applying alternating magnetic field excitation by using a multi-turn micro coil, and acquiring an induced voltage signal; utilizing a phase-locked loop principle to carry out frequency-mixing low-pass filtering processing on the induced voltage signal and a reference signal, demodulating a phase, judging whether the phase corresponding to the induced voltage signal is equal to the phase when no non-conductive particles pass through, if so, determining that a discrete phase is normal, and repeatedly executing the induced voltage signal at the next moment; otherwise, determining that the non-conductive particles pass through the discrete phase; obtaining the phase corresponding to each moment through uninterrupted measurement, and finally, comparing each phase value one by one according to a selected threshold tau, so that the count of the discrete phase non-conductive particles is obtained by counting the number of times of phase abnormality. According to the invention, efficient real-time detection of the flowing discrete phase non-conductive particles is realized.

Description

technical field [0001] The invention belongs to the field of electromagnetic measurement, in particular to a non-contact electromagnetic detection method for discrete-phase non-conductive particles, which is used for detection and counting of discrete-phase non-conductive particles. Background technique [0002] In recent years, with the mass production and use of plastics, the concentration of microplastic particles in the environment has been increasing. Microplastic pollution has become a global environmental problem and has attracted widespread attention from academia and the public. [0003] Microplastics usually refer to plastic particles with a particle size of less than 5 mm, which is a new type of environmental pollutant. At present, researchers have found traces of microplastics in freshwater waters, marine water bodies, terrestrial environments, atmospheric particles, and organisms. The harm is mainly manifested in two aspects: one is that microplastics are not di...

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Problems solved by technology

[0004] However, the traditional physical and chemical detection methods in the prior art have disadvantages such as complex operation process, long detection time and need to contact with the measured object. There are few methods for fast and effective detection and counting of discrete phase non-conductive particles.

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