Plastic film thickness detection device and method based on terahertz time-domain spectroscopy technology

Abstract

The invention discloses a plastic film thickness detection device based on terahertz time-domain spectroscopy technology, which includes a femtosecond laser, a first reflector, a beam splitter, an optical delay line, a second reflector, a terahertz emitter, a first Parabolic mirror, IR filter, sample stage, terahertz detector, third reflector, fourth reflector, terahertz time-domain system controller and computer; also includes detection method: separately collect terahertz waves transmitted through the air and received Measure the signal of the plastic film, set the initial thickness of the plastic film, and calculate its refraction coefficient by substituting the terahertz transfer function model of the thin sample, and then use Fourier transform to transform the refraction coefficient signal into the quasi-space, and calculate the signal amplitude in the quasi-space Peak value; continuously modify the thickness value until the peak value of the quasi-spatial signal amplitude reaches the minimum, and obtain the thickness of the plastic film; the invention can solve the problem of poor detection accuracy of the current plastic film thickness, and can detect the thickness of the plastic film quickly and accurately 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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