The inspection, testing, certification, and testing methods for internal stress of daily glass products and glass instruments mainly rely on a series of professional testing technologies and standards. The following is a detailed description of these methods:

1. Test method
Polarized stress meter method
Principle: Utilize the principle of polarized light interference to quantitatively analyze internal stress by measuring the internal birefringence optical path difference of glass.
Advantages: It has the advantages of non-destructiveness and wide measurement range, and is suitable for internal stress testing of large glass products and complex structures.
Application: It is one of the most commonly used methods for glass internal stress testing and is widely used in internal stress detection of daily glass products and glass instruments.
X-ray diffraction method
Principle: Evaluate internal stress by measuring the changes in the lattice structure inside the glass.
Advantages: It has the advantages of high precision and high sensitivity.
Disadvantages: The operation is complicated and the equipment is expensive, which is suitable for occasions with extremely high precision requirements.
Other methods
Such as the optical interference method, laser speckle method, etc., these methods have their own advantages and disadvantages, and the appropriate test method should be selected according to specific test needs and conditions.
2. Test Standards
GB/T 4545-2007
Scope of application: specifies the test method, test conditions, and determination method of the internal stress of glass bottles and jars.
Application: Through the test of this standard, the internal stress level and distribution of glass bottles and jars can be evaluated to ensure that they meet the relevant standards and customer needs.
YBB00032005-2005
Scope of application: specifies the internal stress test method and requirements of soda-lime glass infusion bottles.
Application: Through the test of this standard, it can be ensured that the internal stress level of soda-lime glass infusion bottles meets the quality requirements of pharmaceutical glass containers.
JJG196-2006
Scope of application: specifies the internal stress test method and requirements of glass measuring tools.
Application: Through the test of this standard, the internal stress level and distribution of glass measuring tools can be evaluated to ensure the accuracy and reliability of their measurement results.
GB/T 15726-2021
Scope of application: It specifies the terms and definitions, principles, specimens, instruments, test steps, result calculation, test reports, etc. of the internal stress test of glass instruments, and is applicable to the internal stress test of glass instruments after annealing.
Main changes: Compared with GB/T 15726-1995, in addition to editorial changes, the main technical changes include the addition of terms and definitions, the modification of the expression method of the test results to result in the calculation, etc.
III. Test steps
Taking the polarization stress meter method as an example, the test steps usually include:

Instrument preparation: Ensure that the polarization stress meter meets the technical requirements, such as uniform light source, polarization degree of polarization element not less than 99%, etc.
Specimen preparation: The specimen should be a glass product after annealing without other tests, and it needs to be placed in the laboratory for a certain period of time in advance to adapt to the environment.
Test environment: Install the stress meter in an environment with a temperature of 10~35℃, relative humidity of less than 80%, and dim light.
Test operation: Operate according to the instrument manual and test standards, adjust the zero point of the stress meter, and measure and record data such as birefringence optical path difference.
Result calculation: According to the test data and the thickness of the glass sample, calculate the optical path difference per unit thickness to indicate the internal stress of the product.
Report preparation: According to the test results and calculated data, prepare a complete test report, including test methods, test conditions, test results, and judgment conclusions.
IV. Precautions
Preparation before testing: Ensure that the test instrument and sample meet the requirements of the test standard to avoid test errors.
Test environment control: The test environment has a great influence on the test results, and the temperature humidity, and other conditions should be strictly controlled.
Test operation specifications: Operate according to the test standards and instrument manual to avoid inaccurate test results caused by operating errors.
Accurate data processing: Accurately process and analyze the test data to ensure the accuracy and reliability of the test results.
In summary, there are many methods for inspection, testing, and certification of internal stress of daily glass products and glass instruments. Appropriate test methods and standards should be selected according to specific test needs and conditions. At the same time, the test steps and precautions should be strictly followed during the test to ensure the accuracy and reliability of the test results.