Home>ASTM Standards>ASTM E969-02(R2019) pdf free download

ASTM E969-02(R2019) pdf free download

ASTM E969-02(R2019) pdf free download.Standard Specification for Glass Volumetric (Transfer) Pipets
1. Scope
1.1 This specification covers volumetric pipets of two classes. Class A, Precision Pipet and Class B, General Purpose. N OTE 1—Specifications for micropipets are given in Specification E193. 1.2 Product with a stated capacity not listed in this standard may be specified class A tolerance when product conforms to the tolerance range of the next smaller volumetric standard product listed in Table 1. 1.3 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Design
4.1 Shape—The pipets shall consist in general of a suction tube and a delivery tube separated by a bulb; all three parts shall be permanently attached together. Any cross-section of the pipet taken in a plane perpendicular to the longitudinal axis shall be circular. The shape shall permit complete emptying and thorough cleaning. 4.1.1 Bulb—The shape shall permit complete emptying without any hold up, and easy cleaning. 4.2 Dimensions—The length ofthe suction tube shall be 150 to 190 mm and the minimum wall thickness ofboth suction and delivery tubes shall be 0.90 mm. Pipets must comply with the essential dimensions given in Table 1. 4.3 Delivery Tips—Delivery tips shall be made with a gradual taper of 1.5 to 3 cm. The end of the tip shall be perpendicular to the longitudinal axis of the tip. The outside edge of the tip may be bevelled slightly and the end and the bevel shall be ground or fire-polished. Sudden constriction at the orifice would impair smooth flow characteristics of the delivery stream and is not acceptable. 4.3.1 Tempered Tips—May be supplied at option of manu- facturer. The tempered tip, when tested in index oil which matches the refractive index of the glass being used, shall have a temper between 75 and 220 nm (millimicrons). 4.4 Markings—All markings shall be permanent and leg- ible.4.4.1 Capacity Line—The capacity line shall be a sharply defined line of uniform width (maximum 0.6 mm) in a plane perpendicular to the vertical axis of the pipet. The line shall be applied by one ofthe following methods: etched and filled with a permanent pigment; etched through a vertical colored stripe fused into the glass; by application ofa stain fired into the glass without etching; or by application of an enamel fired onto the glass without etching. The line shall completely encircle the tube except when the line is a stain fired into the glass without etching. If so stained, the line shall extend a minimum of 90 % of the way around the tube. 4.4.2 Color Coding—Each pipet shall be marked with one or two color bands as specified in Table 1. The single band should be 6 to 10 mm wide, while the double color bands should each be 3 to 5 mm wide and separated by a clear space of 2 to 3 mm. Color bands do not have to be continuous but may be broken as long as they cover 40 % ofthe circumference of the pipet. Colors must be bright and distinct. 4.4.3 Identification Markings—Each pipet marked by one of the methods given in 4.4.1 shall show the manufacturer’s name or trademark, the nominal capacity, the word “delivers” or the symbol “TD,” the temperature of calibration, 20 °C. The letter “A” symbolizing Class A accuracy to appear on all Class A pipets. Class A pipets may be optionally serialized. 4.5 Workmanship—Pipets shall be free of defects which may distort the appearance of the liquid surface or may impair the serviceability.

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