CN111337519A - Method for measuring physical parameters in film production - Google Patents

Abstract

The invention belongs to the technical field of microwave measurement, and particularly relates to a method for measuring physical parameters in film production. The method mainly comprises the following steps: detecting the energy r attenuated by the film passing through the microwave sensor by the microwave sensor_QAnd the frequency deviation delta of the film passing through the microwave sensor is obtained according to the set 10 coefficients_QAnd delta, establishing the unknown quantity as the water content rho of the film_WAnd film basis weight rho_PThe water content rho of the film is obtained by solving the equation system_WAnd film basis weight rho_P. The invention has the beneficial effects that: the method is used for measuring the film parameters, can replace a radiation source, avoids the harm of the radiation source to human bodies and the environment, reduces the management cost and improves the production efficiency; at the same time, can replace the optical measurement method, canThe measurement precision can be greatly improved.

Description

Method for measuring physical parameters in film production

Technical Field

The invention belongs to the technical field of microwave measurement, and particularly relates to a method for measuring physical parameters in film production.

Background

The measurement of physical parameters during production is very important in order to ensure efficient, economical and high quality production of thin films. In the traditional production, the physical parameter monitoring of the film is detected by two methods, namely a radiation method and an optical method. The radiation method causes radiation pollution to the environment, damages production personnel and increases the production cost; although the optical method is pollution-free, the detection range and the detection precision are limited, and the production requirement is difficult to meet.

The microwave can be used for measuring the physical parameters of the film, which has been determined earlier, and a plurality of documents are reported at present, but only microwave moisture detection products are used in the production practice, and other reports are not found. In the film production, the first concerned physical parameter is the weight of a unit square, and the second is the water concentration, the thickness measurement in the film production mainly adopts a radiation method and a small amount of an optical method, and the film thickness and the water concentration are measured by using the same device without reports.

Disclosure of Invention

In view of the above problems, the present invention proposes a method for simultaneously obtaining two physical quantities of thickness and moisture concentration of a thin film by microwave measurement. The traditional microwave resonant cavity method cannot measure the water concentration and the thickness simultaneously because the physical parameters cannot form a proper equation set to solve two physical quantities of the thickness and the water concentration, so the key point of the method is to provide an equation set capable of solving the two physical quantities of the thickness and the water concentration.

The technical scheme of the invention is as follows:

a method for measuring physical parameters in film production comprises the following steps:

s1, detecting two physical parameters r through a microwave sensor_QAnd δ, wherein r_QRepresents the energy attenuated by the film passing through the microwave sensor, and delta represents the frequency offset of the film passing through the microwave sensor;

s2, according to two physical parameters r_QAnd delta for establishing a binary system of quadratic equationsAfter solving the water content rho of the film_WAnd film basis weight rho_P：

r_Q＝K₁₁ρ_W+K₁₂ρ_P+K₁₃ρ_W ²+K₁₄ρ_P ²+K₁₅ρ_Pρ_W

δ＝K₂₁ρ_W+K₂₂ρ_P+K₂₃ρ_W ²+K₂₄ρ_P ²+K₂₅ρ_Pρ_W

Wherein, K₁₁～K₁₅，K₂₁～K₂₅The values of the 10 set coefficients are respectively as follows: -30<K₁₁～K₁₅<50，0<K₂₁<500，0<K₂₄<500，-20<K₂₂<70，-20<K₂₃<70，-20<K₂₅<70；

S3, obtaining the physical parameter r according to the step S1 in the actual production_QAnd delta solving the system of binary quadratic equations established in the step S2 to obtain the water content rho of the film_WAnd film basis weight rho_P。

According to the technical scheme, aiming at the problem that the traditional microwave sensor cannot measure the film quantification and only can measure the water content of the film, a binary quadratic equation set is formed by using measurement parameters obtained by the microwave sensor, and two physical parameters of the water content and the thickness of the film (the film quantification and the thickness can be mutually converted) can be obtained simultaneously by solving the equation set. In the scheme of the invention, K₁₁～K₁₅，K₂₁～K₂₅The 10 coefficients are pre-calibrated values, specific values need to be set according to different targets, and the value range provided by the invention comprises most of film products and can be suitable for most of conditions.

The invention has the beneficial effects that: the method is used for measuring the film parameters, can replace a radiation source, avoids the harm of the radiation source to human bodies and the environment, reduces the management cost and improves the production efficiency; meanwhile, an optical measurement method can be replaced, and the measurement precision can be greatly improved.

Detailed Description

The present invention is further illustrated by the following examples to demonstrate the effectiveness and utility of the invention.

Examples

In this example, the target film is set to be quantitative 95g and the water content is set to be 13.2g, and the measurement is carried out by adopting the method of the invention, which specifically comprises the following steps:

detection of r by a microwave sensor_QAnd δ, each being r_Q＝0.16472，δ＝12.66495；

For the purposes of this example, the set coefficients are:

K₁₁＝0.70384，K₁₂＝-0.00202，K₁₃＝-0.00407，K₁₄＝0.01936，K₁₅＝0.08，

K₂₁＝12.8165，K₂₂＝6.6898，K₂₃＝-5.7145，K₂₄＝60.034，K₂₅＝0.04；

substituting the parameters into a binary quadratic equation set, and solving to obtain:

ρ_P94.45g, error percentage: -0.58%;

ρ_W13.23g, the error percentage is: -0.227%;

if the conventional radioactive source is adopted to measure and obtain the paper quantification of 92.8g, the error percentage is as follows: -1.28%.

If the paper quantitative determination is 90g by adopting an optical method, the error percentage is as follows: -4.44%, paper moisture 12.8g, error percentages: -3.03%.

Therefore, the method of the invention not only meets the requirement of simultaneously measuring the thickness and the water concentration of the film, but also obviously improves the precision compared with the prior art, thereby having stronger practicability.

Claims (1)

1. A method for measuring physical parameters in film production is characterized by comprising the following steps:

s1, detecting two physical parameters by a microwave sensorr_QAnd δ, wherein r_QRepresents the energy attenuated by the film passing through the microwave sensor, and delta represents the frequency offset of the film passing through the microwave sensor;

s2, establishing a binary quadratic equation set:

r_Q＝K₁₁ρ_W+K₁₂ρ_P+K₁₃ρ_W ²+K₁₄ρ_P ²+K₁₅ρ_Pρ_W

δ＝K₂₁ρ_W+K₂₂ρ_P+K₂₃ρ_W ²+K₂₄ρ_P ²+K₂₅ρ_Pρ_W

wherein, K₁₁～K₁₅，K₂₁～K₂₅The values of the 10 set coefficients are respectively as follows: -30<K₁₁～K₁₅<50，0<K₂₁<500，0<K₂₄<500，-20<K₂₂<70，-20<K₂₃<70，-20<K₂₅<70；ρ_WIs the water content of the film, rho_PQuantifying the film;

s3, adopting the physical parameter r obtained in the step S1_QAnd delta solving the system of binary quadratic equations established in the step S2 to obtain the water content rho of the film_WAnd film basis weight rho_P。