ASTM E714-94 (R2021) pdf free download.Standard Specification for Disposable Glass Serological Pipets.
1 .1 This specification covers disposable glass serological pipets, calibrated bto deIiver” used in measuring volumes of liquids.
4. Materials and Manufacture
4.1 The pipets shall be fabricated from borosilicate glass. Type I, Class A or B: or soda-lime glass, Type II. as defined in Specification E438.
5. Design
5.1 Shape—Pipets shall be straight and of one-piece construction. Any cross section of a pipet taken in a plane perpendicular to the longitudinal axis shall he circular.
5.2 Delivery Tips—Delivery tips shall he made with a gradual taper of 10 to 25 mm for capacities up to 2 cm3 inclusive, and 15 to 30 mm for the 5 cm3 and 10cm3 size(s). The tip end shall be reasonably perpendicular to the longitudinal axis of the pipet and shall be flrcpolished.
5.3 Top End—The 10cm3 and 25 cm3 pipet shall have a top end tooled to a diameter of 7 to 9 mm and shall have an overall length of 15 to 25 mm from the top. The top end shall be suitable for plugging with filtering material. All top ends shall he reasonably perpendicular to the longitudinal axis of the pipet, and shall be firepolished.
5.4 Dimensions (111(1 OutflobI’ Times—The limiting dimensions and outflow times shall be as shown in Table 1. Outflow times shall he determined on unplugged pipets. using distilled water at 25 ± 5 °C, and by means of a stopwatch.
6. Markings
6.1 Graduation Markings—Graduation lines shall be between 0.2 and 0.5 mm in width, and in a plane perpendicular to the longitudinal axis of the pipet and parallel to each other. A main graduation line shall extend at least three-fifths of the way around the pipet. The values of all main graduation lines shall he in Arabic numerals directly above the line referenced. Intermediate graduation lines shall extend at least one-fifth of the way around the pipet, and least graduation lines shall extend at least one-seventh of the distance around the pipet. The 0 graduation line shall be at least 90 mm below the top of the pipet on all sizes.ASTM E714 pdf download.