1、Designation: E 1154 89 (Reapproved 2003)Standard Specification forPiston or Plunger Operated Volumetric Apparatus1This standard is issued under the fixed designation E 1154; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers requirements, operating con-ditions, and test methods for piston or plunger operatedvolu
3、metric apparatus (POVA).1.2 This specification includes specifications applicable forall types of POVA or those given by the manufacturer. Thefollowing precautionary caveat pertains only to the test methodportion, Section 13, of this specification: This standard doesnot purport to address all of the
4、 safety concerns, if any,associated with its use. It is the responsibility of the user of thisstandard to establish appropriate safety and health practicesand determine the applicability of regulatory limitations priorto use.2. Referenced Documents2.1 ISO Documents:2ISO 3534 StatisticsVocabulary and
5、 SymbolsISO 653 Long Solid-Stem Thermometers for Precision UseISO 655 Long Enclosed-Scale Thermometers for PrecisionUseISO 4787 Laboratory GlasswareVolumetric GlasswareMethods for Testing and Use3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 accuracy3the accuracy of an instru
6、ment is thecloseness of agreement between the nominal volume and themean volume, obtained by applying the test procedure speci-fied in Section 13 of this specification. It is quantified by theinaccuracy of the mean.3.1.2 dead volumethe dead volume is that part of the totalliquid volume, held in the
7、operational part of the device, whichis not delivered.3.1.2.1 DiscussionThe dead volume should not be con-fused with the dead space of an air displacement instrument.3.1.3 disposablethose parts of an instrument that areintended to be used once only and then discarded. Disposableparts are generally i
8、ntended for use in applications wheresample carryover is intolerable.3.1.4 maximum errorthe maximum difference betweenthe nominal volume and any single individual volume obtainedby applying the test procedure specified in Section 13 of thisISO Standard.3.1.5 maximum expectable errorwith more than 95
9、 %probability, the maximum expectable error is calculated asfollows:61ET1 1 2s! (1)where:ET= inaccuracy of the mean, ands = standard deviation from the repeatability test inSection 13.3.1.6 nominal volume(s)the stated volume(s) for whichperformance is specified.3.1.7 unit of volumethe millilitre or
10、the microlitre, that areaccepted substitutes for the cubic centimetre or cubic millime-tre.3.1.7.1 DiscussionIt is recommended that volumes shouldbe specified in microlitres up to 999 L, and in millilitres from1 mL.3.1.8 piston or plunger operated volumetric apparatus(POVA)the volume of liquid to be
11、 measured with POVA isdefined by one or more strokes of one or more pistons orplungers. POVA may be operated manually or mechanically(for example, electrically, pneumatically or by hydrostaticpressure).3.1.8.1 DiscussionIn the following text the word8 pistonmeans8 piston or plunger.3.1.9 precision3t
12、he closeness of agreement between theindividual volumes obtained by applying the test procedurespecified in this specification. It is quantified by the impreci-sion.3.1.9.1 DiscussionThe test procedure specified gives onlya measure of the repeatability (see ISO 3534) under controlledconditions.3.1.1
13、0 reusablethose parts of an instrument that are meantto be used more than once. As the reusability of some parts canrarely be quantified, any institution or individual who reuses a1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus and is the direct responsibil
14、ity of Subcommittee E41.06 onWeighing Devices.Current edition approved April 4, 1989. Published May 1989. Originallypublished as E 1154-87. Last previous edition E 1154-87.2Available from American National Standards Institute, 1430 Broadway, NewYork, NY 10018.3These definitions apply only in the cas
15、es where the distributions are Gaussian.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.reusable part must see to its safety and effectiveness. Reusableparts are generally intended for use in applications wheresample carryover is tol
16、erable, or can be adequately prevented.3.1.11 sample carryoverthat portion of the sample that isretained in the instrument and that may affect subsequentsamples.3.1.12 stated featureany feature claimed by the manufac-turer.3.1.13 reference temperaturethe temperature at which theinstrument is designe
17、d to deliver its nominal volume(s).3.1.13.1 DiscussionAt that temperature the closest agree-ment between manufacturers performance claims and testresults may be expected.3.1.14 reference temperature rangethat temperaturerange for which the tolerances for accuracy are specified.3.1.15 working rangeth
18、at part (of the total range) forwhich manufacturers performance specifications are given.3.1.16 working temperature rangethat range of tempera-tures for which manufacturers performance specifications aregiven.4. Classification4.1 Types of POVAPiston or plunger operated volumetricapparatus (POVA) are
19、 classified as follows:4.1.1 PipetteA measuring instrument for the transfer of apredetermined volume of liquid from one vessel to another. Itis not connected to a reservoir.4.1.2 DispenserA measuring instrument for deliveringpredetermined volumes of liquid from a reservoir. The reser-voir may be int
20、egrated with the instrument or connectedexternally.4.1.3 DilutorA measuring instrument for taking up differ-ent liquids (for example, sample and diluent) and deliveringthem in combination so as to comprise a predetermined ratio,or predetermined volumes, or both. The reservoir of diluentmay be integr
21、ated with the instrument or connected externally.4.1.4 Displacement BuretA measuring instrument fromwhich the volume delivered is determined by an externalindicator. The volume delivered can then be read.4.2 Types of Displacement:4.2.1 Displacement with an air interface (“air displace-ment”). The de
22、livered liquid is displaced by an air interface(indirect action), (see Figs. 1 and 2).4.2.2 Displacement without an air interface (“positive dis-placement”). The delivered liquid is displaced either by aliquid interface (indirect action) or by actual contact with thepiston (direct action), (see Fig.
23、 3 and Fig. 4).5. Performance Requirements5.1 Performance Tolerances:5.1.1 Performance tolerances specified for POVA are meantto include any thermal drift effect upon the accuracy andprecision attributable to hand-transmitted heat during normaluse. It is, therefore, important that the instrument bei
24、ngevaluated according to the referenced procedure not be pre-conditioned (warmed) by recent handling, nor isolated fromnormal handwarming during the test series (30 or 10 cycles).5.1.2 Volumetric performance tolerances are not specified inthis specification. The manufacturer shall specify the perfor
25、-mance tolerances in terms of the accuracy of the mean ( EC%)and coefficient of variation (CVc%). Values shall be given forthe minimum and maximum volumes of the working range, aswell as for any intermediate volumes in the series 1, 2, 5, 10 5.2 The reference temperature recommended for all POVAis 2
26、1.5C, which is the mid-point of the reference temperaturerange, (see section 3.1.14). The use of another referencetemperature must be stated by the manufacturer.5.2.1 Reference Temperature Range The reference tem-perature range for all POVA shall be 19 to 24C, (see section3.1.13 and section 3.1.14).
27、5.3 Removable Parts:5.3.1 The volumetric performance of POVA to be used withremovable parts can depend to a large extent on the design,material, and workmanship of those parts. The test proceduresdescribed can give information only about the performance ofthe instruments together with the removable
28、parts actuallyused.5.3.2 Single-Measurement TestThe single-measurementment test requires either 30 or 10 randomly selected removableparts, one for each sample of the series. This test evaluates theinstruments performance and component of imprecision dueto the variation of these parts.5.3.3 Replicate
29、-Delivery TestThe replicate delivery testuses one removable part for the 30 or 10 sample series. Thistest evaluates the instruments performance and the componentof imprecision due to the reuse of this part.5.4 DurabilityAny claim by a manufacturer that an in-strument is resistant to any defined cond
30、itions (for example,sterilization and chemical exposure) shall be understood insuch a way that even long term or repeated exposure to thoseFIG. 1 Displacement With an Air Interface (Air Displacement)E 1154 89 (2003)2conditions (as specified by the manufacturer) will not affect therated performance o
31、f the instrument.6. General Operating Conditions6.1 Relationship to PerformanceThe specification of op-erating procedures is critical to the proper functioning of theinstruments, and determines their ability to perform withinspecified tolerances. Changes in the operating mode candramatically alter t
32、he results of analyses. Most instruments arecalibrated for certain operating modes; another manner of usemay result in a change in the accuracy or precision, or both.6.2 DelineationIt is the manufacturers responsibility todelineate the modes of operation in instruction manuals and tostate for which
33、of the modes the instrument is calibrated.6.3 PreparationThe manufacturer shall provide instruc-tions necessary for the preparation of the instrument for use inparticular operating modes (for example, mounting of remov-able parts, method of volume adjustment, temperature equa-tion, isothermal requir
34、ements, testing of piston action, lubrica-tion, priming, purging or prerinsing information, etc.).7. Operating Conditions for Pipetters7.1 Two common modes of operation are in use, the forwardmode (sometimes referred to as normal mode), and the reversemode (usable with two-component stroke mechanism
35、 systemsonly), (see Fig. 3 and Fig. 4).7.1.1 In general, the precision of the repetitive use of theforward mode relies upon the precise draining by air pressure(in the case of air displacement pipetters) or internal wiping ofthe pipet barrel or tip (in the case of displacement pipetters). Ascompared
36、 to the reverse mode, the forward mode is relativelyinsensitive to variations in the speed of the piston or plunger inthe dispensing action. Positive displacement instruments withrelatively small delivery orifices are generally less sensitive tochange in accuracy when handling liquids with high weta
37、bilitycharacteristics.7.1.2 Air displacement pipetters with two-component strokemechanisms are generally less sensitive than air displacementpipetters with one-stroke mechanisms positive displacementpipetters to errors introduced by slight variations of thedynamics of the liquid interface break at t
38、he end of the pipet orFIG. 2 Displacement Without an Air Interface (Positive Displacement)FIG. 3 Pipetter Mode of Operation (Forward Mode)FIG. 4 Pipetter Mode of Operation (Reverse Mode)E 1154 89 (2003)3pipet tip during the dispensing action, due to the purging actionof the air “blow-out” stroke pot
39、ential.7.1.3 The use of the reverse mode with two-componentstroke mechanism pipetters may be more advantageous whenliquids that are difficult to handle in the forward mode areencountered.7.2 Forward Mode, General Format:7.2.1 PreparationPipetter and environment shall be iso-thermal. Volume settings
40、and the mounting of removable ordisposable pipet tips shall be accomplished according to themanufacturers directions.7.2.2 Aspiration:7.2.2.1 Hold the instrument in a vertical position, or asprescribed by the manufacturer.7.2.2.2 In the case of two-component stroke systems, de-press the push button
41、smoothly to the intermediate stopposition.7.2.2.3 In the case of one-component stroke systems, de-press the push-button smoothly to the bottom stop position.7.2.2.4 Immerse the pipet or pipet tip into the liquid to bepipetted to, and maintain it at the following depth:Volume, L Immersion Depth, mm1t
42、o100 2to3101 to 1000 2 to 41.1 to 10 mL 3 to 67.2.2.5 Allow the push-button to move up to the top stopposition slowly and smoothly.7.2.2.6 For air displacement pipetters, observe a wait of 1 s.7.2.2.7 Withdraw the pipet or pipet tip smoothly by liftingstraight up either from the center of the liquid
43、 surface in thevessel, or up the sidewall of the vessel.NOTE 1No further liquid contact of the pipet or pipet tip is allowedonce the liquid interface is broken.7.2.2.8 Wipe the pipet or pipet tip only if there are extrane-ous droplets. Contact with the orifice of the pipet or pipet tip,especially wi
44、th absorbent material, must be avoided, as largecomponents of random or systematic error may be introduced.7.2.3 DeliveryPlace the pipet or pipet tip at an angle (10to 45, or as prescribed by the manufacturer) against the insidewall of the receiving vessel.7.2.3.1 For two-component stroke systems, d
45、epress thepush-button smoothly to the intermediate stop position. After await of 1 s, depress the push-button to the bottom stop positionas the pipet or pipet tip end is removed from the sidewall byeither a sliding action up the wall or a movement away fromthe wall (“touching off”).7.2.3.2 For one-c
46、omponent stroke systems, depress thepush-button smoothly to the bottom stop position as the pipetor pipet tip end is removed from the sidewall by either a slidingaction up the wall, or a movement away from the wall.7.2.3.3 Allow the push-button to move up to the top stopposition.7.3 Reverse Mode, Ge
47、neral Format:7.3.1 PreparationPrepare in accordance with 7.2.1, for-ward mode.7.3.2 AspirationAspirate in accordance with 7.2.2, exceptthat the push-button is depressed to the bottom stop positionprior to pipet tip immersion.7.3.3 Delivery:7.3.3.1 Place the pipet or pipet tip at an angle (10 to 45,
48、oras prescribed by the manufacturer) against the inside wall ofthe receiving vessel.7.3.3.2 Depress the push-button smoothly to the intermedi-ate stop position.7.3.3.3 After a 1-s wait, remove the pipet or pipet tip fromthe sidewall, in accordance with 7.2.3.7.3.3.4 In the case of the pipet tip bein
49、g reused, allow thepush-button to remain in the intermediate stop position forsubsequent immersion for the next pipetting cycle. In the caseof the pipet tip to be changed, allow the push-button to returnto the top stop position.NOTE 2Top and bottom stop positions, as described in the proceduresabove, are not meant to include auxiliary stroke positions (for example, fortip ejection).7.4 Prerinsing (Forward Mode):7.4.1 Prerinsing is the action of precoating the inside of theliquid contracting part(s) with a thin film of the same
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