ASTM E788-97

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 788 – 97
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Specification for
Pipet, Blood Diluting
This standard is issued under the fixed designation E 788; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope bead sufficiently large enough to prevent its being impacted in
the constriction portion of the bulb. The cross section of the
1.1 This specification covers requirements for glass reusable
pipet at any point shall be circular. The distal end of the white
blood diluting pipets that are used for performing red and white
cell pipet shall be pulled to a point and then ground and
cell corpuscle determinations.
polished to a tapered tip. The distal end of the red cell pipet
2. Referenced Documents
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
2.1 ASTM Standards:
pipet shall be 0.2 to 0.5 mm. The external diameter of the
E 694 Specification for Volumetric Ware
ground and polished tip shall not exceed 2.0 mm. The overall
E 920 Specification for Commercially Packaged Laboratory
length of both pipets shall be 104 to 121 mm. The proximal end
Apparatus
may be of funnel design, with an exterior taper, or ground and
E 921 Specification for Export Packaged Laboratory Appa-
polished with a taper of sufficient angle to permit application of
ratus
a rubber suction tube or other suction device (see Fig. 2).
E 1133 Practice for Performance Testing of Packaged Labo-
5.2 Capacity—The capacity of the red cell pipet bulb shall
ratory Apparatus for United States Government Procure-
be 0.8 to 1.2 cm and the capacity of the white cell bulb shall be
ments
0.2 to 0.4 cm . The capacity of the red cell pipet stem (bulb to
E 1157 Specification for Sampling and Testing of Reusable
distal end) shall be 0.008 to 0.012 cm and the capacity of the
Laboratory Glassware
white cell pipet stem shall be 0.02 to 0.04 cm .
3. Classification
5.3 Capacity Markings:
5.3.1 Pipet Bulb Markings—The red and white cell pipet
3.1 This specification covers two different pipet designs and
bulb capacity shall be confined to and indicated by calibration
permissible alternatives.
lines on the pipet. These lines shall be located on both sides of
3.1.1 Red and white cell blood diluting pipets (see Fig. 1).
the bulb and shall be within 2 mm to 6 mm above the bulb
3.1.2 Permissible alternative designs (see Fig. 2).
(proximal end) and within 3 mm to 6 mm below the bulb (distal
4. Materials
end). The exact manner for measuring these line placements is
specified in Fig. 1.
4.1 The pipets shall be made of common spirit bore white
5.3.2 Pipet Stem Markings—The graduation lines on the
back tubing or clear glass with a white stripe applied to the
stem of the red and white cell pipets shall be equally divided
outer surface of the tubing.
into two or ten divisions. If there are two divisions, the two
4.2 The beads shall be made of glass or ceramic composi-
calibration lines on the stem will be numbered 0.5 and 1. If
tion and shall be of red, clear, or white coloring.
there are ten divisions, the ten calibration lines will be
5. Dimensions and Permissible Variations
numbered 0.5 on the fifth line and 1 on the tenth line
respectively. The top line (above bulb at the proximal end)
5.1 Design—The red and white cell blood dilution pipets
shall be numbered 101 on the red cell pipet and 11 on the white
shall consist of a small uniform bore glass tube which shall
cell pipet, representing stem and bulb volume collectively. At
have a bulb of proper size near the proximal end (see Fig. 1).
the option of the manufacturer, pipet stems may be graduated
As an alternative, the pipets may be constructed of three pieces
with split lines or partial length lines (see Fig. 2).
of glass that are fused together to form a one-piece pipet (see
5.4 Graduation Lines—All graduation lines on the red and
Fig. 2). The bulb shall contain a nonspherical glass or ceramic
white cell pipets shall be at right angles to the pipet axis and
parallel to each other. The thickness of the graduation lines
This specification is under the jurisdiction of ASTM Committee E-41 on
shall not exceed 0.4 mm.
Laboratory Apparatus and is the direct responsibility of Subcommittee E41.01 on
Glass Apparatus. 5.5 Accuracy—The red and white cell pipet bulb volume
Current edition approved Nov. 10, 1997. Published February 1998. Originally
shall be a volumetric ratio to the stem volume. The red cell
published as E 788 – 81. Last previous edition E 788 – 93.
pipet bulb to stem ratio shall be 100:1 and the white cell pipet
Annual Book of ASTM Standards, Vol 14.02.
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