ASTM E1272-02(2019)

1.1.1 Class A—Each cylinder of precision grade shall be marked with the letter “A” to signify compliance with applicable construction and accuracy requirements. Cylinders may be marked with an identification number (serial number) at the option of the manufacturer.

1.1.2 Class B—General purpose cylinders are of the same basic design as Class A cylinders. However, volumetric tolerances for Class B cylinders shall be within twice the specified range allowed for Class A cylinders. These cylinders need not be marked with their class designation.

1.1.3 Product with a stated capacity not listed in this standard may be specified in Class A tolerance when product conforms to the tolerance range of the next smaller volumetric standard product listed in Table 1.