ASTM E788-97(R2019) pdf free download

ASTM E788-97(R2019) pdf free download.Standard Specification for Pipet, Blood Diluting
5. Dimensions and Permissible Variations
5.1 Design—The red and white cell blood dilution pipets shall consist of a small uniform bore glass tube which shall have a bulb of proper size near the proximal end (see Fig. 1). As an alternative, the pipets may be constructed of three pieces of glass that are fused together to form a one-piece pipet (see Fig. 2). The bulb shall contain a nonspherical glass or ceramic bead sufficiently large enough to prevent its being impacted in the constriction portion of the bulb. The cross section of the pipet at any point shall be circular. The distal end of the white cell pipet shall be pulled to a point and then ground and polished to a tapered tip. The distal end of the red cell pipet shall be ground and polished to a tapered tip. The inside diameter (ID) of the pipet bore at the tip end of the white cell pipet shall be 0.2 to 0.5 mm. The external diameter of the ground and polished tip shall not exceed 2.0 mm. The overall length ofboth pipets shall be 104 to 121 mm. The proximal end may be of funnel design, with an exterior taper, or ground and polished with a taper ofsufficient angle to permit application of a rubber suction tube or other suction device (see Fig. 2). 5.2 Capacity—The capacity of the red cell pipet bulb shall be 0.8 to 1.2 cm 3 and the capacity ofthe white cell bulb shall be 0.2 to 0.4 cm 3 . The capacity of the red cell pipet stem (bulb to distal end) shall be 0.008 to 0.012 cm 3 and the capacity of the white cell pipet stem shall be 0.02 to 0.04 cm 3 .5.3 Capacity Markings: 5.3.1 Pipet Bulb Markings—The red and white cell pipet bulb capacity shall be confined to and indicated by calibration lines on the pipet. These lines shall be located on both sides of the bulb and shall be within 2 mm to 6 mm above the bulb (proximal end) and within 3 mm to 6 mm below the bulb (distal end). The exact manner for measuring these line placements is specified in Fig. 1. 5.3.2 Pipet Stem Markings—The graduation lines on the stem of the red and white cell pipets shall be equally divided into two or ten divisions. If there are two divisions, the two calibration lines on the stem will be numbered 0.5 and 1. If there are ten divisions, the ten calibration lines will be numbered 0.5 on the fifth line and 1 on the tenth line respectively. The top line (above bulb at the proximal end) shall be numbered 101 on the red cell pipet and 11 on the white cell pipet, representing stem and bulb volume collectively. At the option of the manufacturer, pipet stems may be graduated with split lines or partial length lines (see Fig. 2). 5.4 Graduation Lines—All graduation lines on the red and white cell pipets shall be at right angles to the pipet axis and parallel to each other. The thickness of the graduation lines shall not exceed 0.4 mm. 5.5 Accuracy—The red and white cell pipet bulb volume shall be a volumetric ratio to the stem volume. The red cell pipet bulb to stem ratio shall be 100:1 and the white cell pipet bulb to stem ratio shall be 10:1 when tested in accordance with 6.1 and 6.2. 5.6 Workmanship: 5.6.1 The pipets shall be free of defects that detract from their appearance or impair their serviceability. 5.6.2 Construction shall be such that the mechanical strength is provided to withstand the rigors of normal use. The pipets shall be free of strain when tested in accordance with 6.4. 5.7 Identification—Each pipet shall have the name or regis- tered trademark of the manufacturer. These markings are to be located on the stem ofthe pipet directly opposite the graduation lines. The manufacturer has the option to state the pipet volumetric tolerances on the pipet. These tolerances may be located on the stem or the proximal end of the pipet. 5.7.1 The white cell pipet shall have a clear or white glass or ceramic bead sealed within the bulb to identify it readily as a white cell pipet.