# ASTM F1326-02 (Reapproved 2016)

Designation: F1326 − 02 (Reapproved 2016) An American National StandardStandard Test Method forMeasuring Maximum Dry Volume of Utility VacuumCleaners1This standard is issued under the fixed designation F1326; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (´) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is applicable to any vacuum cleanerthat is classified as a utility vac.1.2 The values stated in inch-pound units are to be regardedas standard. The values in parentheses are for information only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Significance and Use3.1 This test method describes a procedure to determine themaximum functional dry volume that the utility vac is capableof collecting.4. Apparatus4.1 Temperature and humidity indicators, to provide tem-perature measurements accurate to within 61°F (61⁄2 °C) andhumidity measurements accurate to within 62 % relativehumidity.4.2 Weighing Scale, the scale shall be accurate to 4 oz (114g) and have a weighing capacity of at least 120 lb (54.4 kg).5. Materials5.1 Water.6. Sampling6.1 A minimum of three units of the same model vacuumcleaner selected at random in accordance with good statisticalpractice shall constitute the population sample.6.1.1 To determine the best estimate of maximum dryvolume for the population of the vacuum cleaner model beingtested, the arithmetic mean of the maximum dry volume of thesample from the population shall be established by testing it toa 90 % confidence level within 65 % of the mean value of themaximum dry volume.6.1.2 Annex A1 provides a procedural example for deter-mining the 90 % confidence level and when the sample sizeshall be increased.NOTE 1—See Annex A1 for a method for determining 90 % confidencelevel.7. Conditioning7.1 Test Room—The test room should be maintained at 70°F6 5°F (21°C 6 3°C) and 45 to 55 % relative humidity.7.2 Condition the water in accordance with 7.1.8. Procedure8.1 Dry Pick Up Capacity:8.1.1 Calculate the volume in gallons of the dust drum usingthe appropriate formulas, neglecting all projections into thedrum.8.1.2 Calculate all projections into the drum using theappropriate formulas in gallons.8.1.3 Subtract the total projection volumes from the dirtdrum volume to arrive at the maximum dry volume. Rounddown to the nearest1⁄4 gal (0.936 L).8.1.4 Record the maximum functional volume in gallons(litres) within1⁄4 gal (0.936 L).9. Procedure9.1 Dry Pick Up Capacity (Alternative Method):9.1.1 An alternative method is allowed when the shape ofthe vacuum cleaner is irregular, and the calculations of Section8 become complex.9.1.1.1 Block the inlet of the dust drum and fill it with water.9.1.1.2 Line the projections into the drum with an appropri-ate water-proof material and submerse into the dust drum.1This test method is under the jurisdiction ofASTM Committee F11 on VacuumCleaners and is the direct responsibility of Subcommittee F11.23 on Filtration.Current edition approved April 1, 2016. Published April 2016. Originallyapproved in 1991. Last previous edition approved in 2011 as F1326 – 02 (2011).DOI: 10.1520/F1326-02R16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States19.1.1.3 Allow the excess water to flow out of the dust drumand then measure the volume of the water remaining in the dustdrum. Round down to the nearest1⁄4 gal.9.1.1.4 Record the maximum functional volume in gallons(litres) within1⁄4 gal (0.936 L).9.1.1.5 Repeat steps 9.1.1 – 9.1.1.4 two more times. Theaverage of the three tests represents the maximum dry func-tional volume that the utility vacuum is capable of collecting.10. Precision and Bias310.1 Precision—These precision statements are based on aninterlaboratory test involving six (6) laboratories and four (4)units. The range of maximum functional volume of the unitswas from 4.8 to 14.6 gal.10.2 The statistics have been calculated as recommended inPractice E691.10.3 The following statements regarding repeatability limitand reproducibility limit are used as directed in Practice E177.10.4 Repeatability (Single-Operator-and Laboratory;Multi-Day Testing)—The ability of a single analyst to repeatthe test within a single laboratory.10.4.1 The expected standard deviation of repeatability ofthe measured results within a laboratory srhas been found to bethe respective values listed in Table 1.10.4.2 The 95 % repeatability limit within a laboratory, r,has been found to be the respective values listed on Table 1,where r = 2.8 (Sr).10.4.3 With 95 % confidence, it can be stated that within alaboratory a set of measured results derived from testing a unitshould be considered suspect if the difference between any twoof the three values is greater than the respective value of therepeatability limit r, listed in Table 1.10.4.4 If the absolute value of the difference of any pair ofmeasured results from three test runs performed within a singlelaboratory is not equal to or less than the respective repeatabil-ity limit listed in Table 1, that set of test results shall beconsidered suspect.10.5 Reproducibility (Multi-day Testing and Single Opera-tor within Multiple Laboratories)—The ability to repeat the testwithin laboratories.10.5.1 The expected standard deviation of reproducibility ofthe average of a set of measured results between multiplelaboratories, SRhas been found to be the respective valueslisted in Table 1.10.5.2 The 95 % reproducibility limit within a laboratory, R,has been found to be the respective values listed in Table 1,where R = 2.8(SR).10.5.3 With 95 % confidence, it can be stated that theaverage of the measured results from a set of three test runsperformed in one laboratory, as compared to a secondlaboratory, should be considered suspect if the differencebetween those two values is greater than the respective valuesof the reproducibility limit, R, listed in Table 1.10.5.4 If the absolute value of the difference between theaverage of the measured results from the two laboratories is notequal to or less than the respective reproducibility limit listedin Table 1, the set of results from both laboratories shall beconsidered suspect.10.6 Bias—No justifiable statement can be made on the biasof the method to evaluate maximum dry volume of utilityvacuum cleaners. Since the true value of the property cannot beestablished by an acceptable referee method.11. Keywords11.1 dry volume; filtration; utility vacuum cleaner3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:F11-1009.TABLE 1 Repeatability and ReproducibilityMax. FunctionalVolume (gallons)Standard Deviation ofRepeatability,SrRepeatability Limit,rStandard Deviation ofReproducibility,SRReproducibility Limit,R5 gal. and less 0.068 0.190 0.380 1.063Over 5 gal. 0.118 0.3297 0.468 1.3116F1326 − 02 (2016)2ANNEX(Mandatory Information)A1. DETERMINATION OF THE POPULATION MEAN HAVING 90 % CONFIDENCE INTERVALA1.1 TheoryA1.1.1 The most common and ordinarily the best singleestimate of the population mean, µ, is simply the arithmeticmean, X¯, of the individual scores (measurements) of the unitscomprising a sample taken from the population. The averagescore of these units will seldom be exactly the same as thepopulation mean; however, it is expected to be fairly close sothat in using the following procedure it can be stated with 90 %confidence that the true mean of the population, µ, lies within5 % of the calculated mean, X¯, of the sample taken from thepopulation.A1.1.2 The following procedure provides a confidence in-terval about the sample mean that is expected to bracket µ, thetrue population mean, 100(1 − α) % of the time where α is thechance of being wrong. Therefore, 1 − α is the probability orlevel of confidence of being correct.A1.1.3 The desired level of confidence is 1 − α = 0.90 or90 % as stated in Section 6. Therefore α = 0.10 or 10 %.A1.1.4 Compute the mean X¯, and the standard deviation, s,of the individual scores of the sample taken from the popula-tion:X¯51n(i51nXi(A1.1)s 5!n(i51nXi22S(i51nXiD2n~n 2 1!where:n = number of units tested, andXi= the value of the individual test unit score of the ith testunit. As will be seen in the procedural example tofollow, this is the average value of the results from threetest runs performed on an individual test unit with theresulting set of data meeting the repeatability require-ments of Section 10.A1.1.5 Determine the value of the t statistic for n –1degrees of freedom (df) from Table A1.1 at a 95 % confidencelevel.NOTE A1.1—The value of t is defined at t1-α/2and is read as “t at 95 %confidence”.t statistic 5 t12α/25 t0.95(A1.2)where:1–α/2 = 1 – 0.10/2=1–0.05 = 0.95, or 95 %.A1.1.6 The following equations establish the upper andlower limits of an interval centered about X¯that will providethe level of confidence required to assert that the true popula-tion mean lies within this interval:CIU5 X¯1ts/=n (A1.3)CIL5 X¯1ts/=n (A1.4)where:CI = confidence interval (U – upper limit; L – lower limit),X¯= mean score of the sample taken from the population,t = t statistic from Table A1.1 at 95 % confidence level,s = standard deviation of the sample taken from thepopulation, andn = number of units tested.A1.1.7 It is desired to assert with 90 % confidence that thetrue population mean, µ, lies within the interval, CIUto CIL,centered about the sample mean, X¯. Therefore, the quantityts/=n shall be less than some value, A, which shall be 5 % ofX¯in accordance with the sampling statement of 6.1.A1.1.8 As n→∞, ts/=n →0.As this relationship indicates,a numerically smaller confidence interval may be obtained byusing a larger number of test units, n, for the sample.Therefore, when the standard deviation, s, of the sample islarge and the level of confidence is not reached after testingthree units, a larger sample size, n, shall be used.A1.2 ProcedureA1.2.1 Agraphical flow chart for the following procedure isshown in Fig. A1.1.A1.2.2 Select three units from the population for testing asthe minimum sample size.A1.2.3 Obtain individual test unit scores by averaging theresults of three test runs performed on each of the threeindividual test units. The data set resulting from the three testruns performed on each individual test unit shall meet therespective repeatability requirement found in Section 10.A1.2.4 Compute X¯and s of the sample.A1.2.5 Compute the value of A where A = 0.05 (X¯).TABLE A1.1 Percentiles of the t Distributiondf t0.951 6.3142 2.9203 2.3534 2.1325 2.0156 1.9437 1.8958 1.8609 1.83310 1.81211 1.79612 1.78213 1.77114 1.76115 1.753F1326 − 02 (2016)3A1.2.6 Determine the statistic t for n - 1 degrees of freedomfrom Table A1.1 where n = the number of test units.A1.2.7 Compute ts/=n for the sample and compare it to thevalue to A.A1.2.8 If the value of ts/=n.A, an additional unit from thepopulation shall be selected and tested, and the computationsof A1.2.3 – A1.2.7 repeated.A1.2.9 If the value of ts/=n,A, the desired 90 % confi-dence level has been obtained. The value of the final X¯may beused as the best estimate of the maximum dry volume for thepopulation.A1.3 ExampleA1.3.1 The following data are chosen to illustrate how thevalue of maximum functional volume for the population ofutility vacuum cleaners is derived. For this particular example,the measured volume test results from three test runs on eachunit are required to have a repeatability limit not exceeding0.190 as indicated in Table 1 for units of 5 gal and less.A1.3.2 Select three test units from the vacuum cleanermodel population. A minimum of three test runs shall beperformed using each test unit.A1.3.3 Test run scores for test unit No. 1:Test run No. 1 = 4.9Test run No. 2 = 5.2Test run No. 3 = 4.8A1.3.4 Maximum spread = 5.2 – 4.8 = 0.4. This value isgreater than the repeatability limit required in Table 1. Theresults shall be discarded and three additional test runs per-formed.A1.3.5 Test run scores for test unit No. 1:Test run No. 4 = 4.9FIG. A1.1 Testing Procedure FlowchartF1326 − 02 (2016)4Test run No. 5 = 5.1Test run No. 6 = 5.1A1.3.6 Maximum spread = 5.1 – 4.9 = 0.1. This value is lessthan the repeatability limit requirement of Table 1.A1.3.7 Unit No. 1 score (4.9 + 5.1 + 5.1)/3 = 5.0.NOTE A1.2—If it is necessary to continue repeated test run sets (7, 8,9–10, 11, 12-etc.) because the spread of data within a data set is not lessthan the repeatability limit requirement stated in Table 1, there may be aproblem with the test equipment, the execution of the test procedure, orany of the other factors involved in the test procedure. Considerationshould be given to re-evaluating all aspects of the test procedure for thecause(s).A1.3.8 A minimum of two additional test units must betested, each meeting the repeatability limit requirement. Forthis procedural example, assume those units met the repeat-ability requirement and the individual unit scores area:Score of test unit No.1=5.0Score of test unit No.2=5.1Score of test unit No.3=4.9A1.3.9 X¯= 1/3 (5.0 + 5.1 + 4.9) = 5.0A1.3.10s 5=3@~5.0!31~5.1!21~4.9!2# 2 @5.015.114.9#23~3 2 1!(A1.5)s = 0.1A1.3.11 A = 0.05 (5.0) = 0.25.A1.3.12 Degrees of freedom, n −1=3−1=2;t0.95statistic= 2.920.A1.3.13 ts/=n51.920~0.1! /=350.168A1.3.14 The requirement that ts/=n,A has been met be-cause A is larger.A1.4 Thus, the value of X¯, 5.0 gal represents the maximumfunctional volume of the utility vacuum and may be used as thebest estimate of the volume for the population mean.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. 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