This part of GB/T9966 specifies the principle, equipment, sample preparation, test procedure, test results and test report of natural stone linear thermal expansion coefficient test. This section applies to the determination of the linear thermal expansion coefficient of natural stone. Mechanical measurement (method A) is applicable to stones with a maximum particle size greater than 7 mm, and dilatometer measurement (method B) is applicable to stones with a maximum particle size not greater than 7 mm.