What is the verification regulation for marble square ruler

1. Appearance inspection

The appearance must not have visible defects such as cracks, dents, looseness, etc

2. Surface roughness detection

The surface roughness of the measuring surface, reference surface, and side surface is required by the national standard to be ground for large surfaces, and polished for other surfaces when not requested by the customer.

3. Flatness

The flatness of the measuring surface is strictly controlled according to the calibration requirements, generally not exceeding 5 microns

4. Parallelism

The flatness of the working surface is 0.05, so the parallelism generally does not exceed 0.1

5. The perpendicularity of the side surface relative to the base surface is generally not higher than 0.02mm