Terahertz time domain spectrum technology-based plastic film thickness detection device and method

Abstract

The invention discloses a terahertz time domain spectrum technology-based plastic film thickness detection device. The terahertz time domain spectrum technology-based plastic film thickness detection device includes a femtosecond laser, a first reflector, a beam splitter, an optical delay line, a second reflector, a terahertz emitter, a first parabolic mirror, an IR filter, a sample table, a terahertz detector, a third reflector, a fourth reflector, a terahertz time domain system controller and a computer. The detection method includes the following steps that: signals generated when terahertz waves pass through the air and a detected plastic film are acquired respectively, and the initial thickness of the plastic film is set and is substituted into a terahertz transmission function model of interaction of the terahertz waves and a film sample, so that the refractive index of the film sample can be calculated, and refractive index signals are transformed into a quasi space through utilizing Fourier transform, and the peak value of the amplitude of the signals in the quasi space is obtained; and a thickness value is modified constantly until the peak value of the amplitude of the signals in the quasi space is minimum, so that the thickness of the plastic film can be obtained. With the terahertz time domain spectrum technology-based plastic film thickness detection device and method of the invention adopted, the problem of poor accuracy of thickness detection of the plastic film at the present can be solved, and the thickness of the plastic film can be fast and accurately detected in real time.

Description

technical field [0001] The invention relates to a plastic film thickness detection device and method, in particular to a plastic film thickness detection device and method based on terahertz time-domain spectroscopy technology, belonging to the field of non-destructive and rapid detection of plastic films. Background technique [0002] At present, there is no effective means of online monitoring in the production of most plastic films and coated products; even in some fields, micrometers are still used to measure the thickness of films of tens of microns or less than ten microns, which is inevitable. Large measurement and reading errors will be introduced, resulting in low measurement accuracy. However, the rapid development of industrial and agricultural production now puts forward higher requirements for the thickness measurement of plastic films. Traditional measurement methods are far from meeting the needs of development. Therefore, it is necessary to find new high-prec...

AI Technical Summary

Problems solved by technology

[0011] Aiming at the problems existing in the above-mentioned prior art, the present invention provides a plastic film thickness detection device and method based on terahertz time-domain spectroscopy technology, which can solve the current problem of poor detection accuracy of plastic film thickness and overcome the measurement accuracy of traditional methods. Low, slow response and susceptible to environmental influences, further real-time, fast and accurate detection of plastic film thickness

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