ASTM E672-87(2011)
(Specification)Standard Specification for Disposable Glass Micropipets
Standard Specification for Disposable Glass Micropipets
ABSTRACT
This specification covers two different types of disposable glass micropipets, calibrated “to contain,” used in measuring microlitre volumes of liquids. The pipets made to these specifications shall be fabricated from borosilicate glass (Type I, Class A or B) or soda lime glass (Type II). Pipets shall be of one piece construction and shall meet the specified requirements for shape, dimensions, and capacity. The calibration line and identification markings such as color code marking are illustrated. The methods of reading and setting a liquid meniscus and a mercury meniscus are detailed. Capacity test shall be performed and calculation of micropipet volume shall be taken using the given formula.
SCOPE
1.1 This specification covers two different types of disposable micropipets, calibrated "to contain," used in measuring microlitre volumes of liquids.
1.2 The values stated in SI units are to be regarded as the standard.
1.3 The following precautionary caveat pertains only to paragraph 9.1.1 of this specification. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:E672 −87 (Reapproved 2011)
Standard Specification for
Disposable Glass Micropipets
This standard is issued under the fixed designation E672; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.3 repeatability—the closeness of agreement between the
individual volumes obtained by applying the test procedure
1.1 This specification covers two different types of dispos-
specified in 9.4.2. It is quantified by the imprecision.
able micropipets, calibrated “to contain,” used in measuring
microlitre volumes of liquids.
4. Classification
1.2 The values stated in SI units are to be regarded as the
4.1 This specification covers two different pipet designs as
standard.
follows:
1.3 The following precautionary caveat pertains only to
4.1.1 Type I—Disposable micropipets with calibration line
paragraph 9.1.1 of this specification. This standard does not
and color coding (see Fig. 1 and Table 1).
purport to address all of the safety concerns, if any, associated
4.1.2 Type II—Disposable micropipets void of markings
with its use. It is the responsibility of the user of this standard
(see Fig. 2 and Table 2).
to establish appropriate safety and health practices and
NOTE 2—Type I pipets were originally specified by the Department of
determine the applicability of regulatory limitations prior to
Defense under MIL-P-36722.
use.
5. Materials and Manufacture
2. Referenced Documents
5.1 The pipets made to these specifications shall be fabri-
2.1 ASTM Standards:
cated from borosilicate glass,Type I, ClassAor B or soda lime
E438 Specification for Glasses in Laboratory Apparatus
glass, Type II, in accordance with Specification E438.
2.2 ISO Standard:
R-1769 Color Coding for Pipets 6. Dimensions and Permissible Variations
6.1 Design—Pipets shall be of one piece construction in
3. Terminology
accordance with Table 1 and Table 2 for shape, dimensions,
3.1 Definitions of Terms Specific to This Standard:
and permissible variations. Any cross-section of the pipet,
3.1.1 accuracy—the closeness of agreement between the
taken in a plane perpendicular to the longitudinal axis, shall be
nominal value and the mean volume, obtained by applying the
circular.
test procedure specified in 9.4.1. It is quantified by the
6.2 Capacity—The pipet capacity shall be stated on the
inaccuracy of the mean (bias).
packagelabel,expressedasµL(microlitre);thisshallbeknown
3.1.2 disposable micropipet—such micropipets will only be
as the stated capacity, V , in making subsequent calculations.
expected to provide their specified performance during their
The expected deviation from the stated capacity shall be
original use or operation.
expressed as accuracy and coefficient of variation and shall be
tested for capacity as specified in 9.1. The unit, microlitre, µL,
NOTE 1—The descriptions of “accuracy” and “repeatability” apply only
in cases where the distributions are Gaussian. may be considered as equivalent to 0.001 cm .
6.2.1 Accuracy (see 4.1)—The accuracy shall be determined
as specified in 9.4 and shall be within the limits given in Table
This specification is under the jurisdiction of ASTM Committee E41 on
1 and Table 2.
Laboratory Apparatus and is the direct responsibility of Subcommittee E41.01 on
6.2.2 Coeffıcient of Variation (see section 4.2)—The coeffi-
Apparatus.
cient of variation shall be determined as specified in 9.4 and
Current edition approved Dec. 1, 2011. Published December 2011. Originally
approved in 1978. Last previous edition approved in 2006 as E672 – 87 (2006).
shall be within the limits given in Table 1 and Table 2.
DOI: 10.1520/E0672-87R11.
6.3 Capacity Mark—Pipets in Fig. 1 shall have a capacity
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
line that is calibrated “to contain” a volume of liquid at 20°C.
Standards volume information, refer to the standard’s Document Summary page on
The capacity line shall be 0.3 to 0.5 mm wide and shall
the ASTM website.
completely encircle the pipet in a plane perpendicular to its
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. longitudinal axis.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E672−87 (2011)
FIG. 1 Type I Pipet
TABLE 1 Dimensions for Type I Pipet
Maximum Volumetric Deviation
Stated Capacity, Minimum Di- Minimum Wall
Color Code Coefficient of
µL ameter A, mm B, mm Accuracy, %
Variation, %
5 white 1.0 0.35 ±1.0 <1.5
10 orange 1.0 0.25 ±0.5 <1.0
20 black 1.1 0.25 ±0.5 <1.0
25 2 white 1.1 0.25 ±0.5 <1.0
50 green 1.3 0.20 ±0.5 <1.0
100 blue 1.6 0.20 ±0.5 <1.0
200 red 2.2 0.20 ±0.5 <1.0
FIG. 2 Type II Pipet
6.4 Identification Markings: 6.4.2 Type II—Pipets in Fig. 2 are devoid of any markings
6.4.1 Type I—The pipets in Fig. 1 shall be identified for and shall be identified for capacity on the package label.
capacity by a color code marking on each pipet consisting of
one or two color bands (see Table 1). For a code consisting of
7. Workmanship, Finish, and Appearance
one band, the band shall be from 2 to 6 mm wide; for a code
7.1 The pipets in Fig. 1 and Fig. 2 shall be free of defects
consistingoftwobands,eachbandshallbe2to6mmwideand
that will detract from their appearance or may impair their
separated with a space of 2 to 6 mm. The color code band, or
serviceability. The pipets shall be free of significant foreign
bands, shall completely encircle the pipet in a plane perpen-
matter, loose or embedded lint or chips that affect the bore, or
dicular to its longitudinal axis. The location of color band, or
stains when viewed under normal room lighting.
bands, shall be as specified in Fig. 1 with the selection of color,
to designate capacity, according to ISO Recommendation 7.2 ThecalibrationlineandcolorcodeonTypeIpipetsshall
R-1769. beappliedtotheglasspipetatlocationsspecifiedinFig.1.The
E672−87 (2011)
TABLE 2 Dimensions for Type II Pipet
Maximum Volumetric Deviation
Stated Capacity, Minimum Minimum Di- Minimum Wall
Coefficient of
µL Length A, mm ameter B, mm C, mm Accuracy, %
Variation, %
1 20 0.5 0.20 ±1.5 <2.0
2 20 0.5 0.20 ±1.2 <1.5
3 20 0.6 0.20 ±1.2 <1.5
4 20 0.6 0.20 ±1.2 <1.5
5 20 0.6 0.20 ±1.2 <1.5
10 20 0.6 0.10 ±1.0 <1.2
20 20 0.6 0.10 ±1.0 <1.2
25 30 0.6 0.10 ±1.0 <1.2
50 30 1.0 0.10 ±1.0 <1.2
100 50 1.3 0.10 ±1.0 <1.2
calibration line shall be sufficiently deposited on the glass to tangent to the plane of the lower edge of the graduation line.
enable the setting of a meniscus and the color band shall be The position of the meniscus is obtained by having the eye in
sufficiently deposited on the glass to identify the pipet as to its the same plane of the lower edge of the graduation line.
stated volume. 8.2.1.2 Method B—The position of the highest point of the
meniscus with reference to the graduation line is such that it is
8. Reading and Setting the Meniscus
in the plane of the middle of the graduation line. This position
of the meniscus is obtained by making the setting in the center
8.1 Reading a Liquid Meniscus (Type I only)—For all
oftheellipseformedbythegraduationlineonthefrontandthe
pipets,thereadingismadeonthelowestpointofthemeniscus.
back of the tube as observed by having the eye slightly above
In order that the lowest point may be observed, it is necessary
the plane of the graduation line. The setting is accurate if, as
to place a shade of some dark material immediately below and
the eye is lowered and the ellipse narrows, the highest point of
behind the meniscus, which renders the profile of the meniscus
the meniscus remains midway between the front and rear
dark and clearly visible against a light background.
portions of the graduation line. By this method it is possible to
8.1.1 Setting a Liquid Meniscus—Setting of the meniscus
observe the approach of the meniscus from either above or
shall be p
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.