1、Designation: F 1890 09An American National StandardStandard Test Method forMeasuring Softball Bat Performance Factor1This standard is issued under the fixed designation F 1890; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar 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 covers a method for determining batperformance by measuring the bat-ball coefficient of restitu
3、tion(BBCOR), deriving the bat performance factor (BPF) andcalculating a batted ball speed (BBS). It is applicable tosoftball bats of any construction or material. The methodprovides a quantitative measure of bat dynamic performancethat may be used for comparison purposes.1.2 The BBCOR, BPF, and BBS
4、are each calculated frommeasurements taken in the laboratory on test equipmentmeeting the requirements defined in this specification.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for
5、information onlyand are not considered standard.1.4 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 reg
6、ulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:2F 1887 Test Method for Measuring the Coefficient of Res-titution (COR) of Baseballs and SoftballsF 1888 Test Method for Compression-Displacement ofBaseballs and SoftballsF 2398 Test Method for Measuring Moment of Inertia an
7、dCenter of Percussion of a Baseball or Softball Bat3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 balance point, ndistance to the center of mass of abat when measured from the distal end of the bat knob.3.1.2 bat-ball coeffcient of restitution (BBCOR), nCORof a specific ball
8、colliding with a bat as defined in this testmethod. See coeffcient of restitution (COR).3.1.3 bat performance factor (BPF), nratio of BBCOR toball COR as defined in this test method.3.1.4 center of percussion (COP), nalso known as thecenter of oscillation, the length of a simple pendulum with thesam
9、e period as a physical pendulum, as in a bat oscillating ona pivot. Forces and impacts at this location will not induceaxial reactions at the pivot point.3.1.5 coeffcient of restitution (COR), nmeasure of impactefficiency calculated as the relative speed of the objects afterimpact divided by the rel
10、ative speed of the objects beforeimpact.3.1.6 moment of inertia (MOI), nmeasure of mass distri-bution relative to an axis of rotation. It is the product of themass multiplied by the square of the distance to the mass,summed over the entire bat.4. Significance and Use4.1 This test method offers a lab
11、oratory means to comparethe performance of a softball bat.4.2 Use of this test method can provide sports governingbodies a means to compare calculated BBS and other physicalproperties of bats.5. Apparatus5.1 Test BallsOfficial softballs approved for play andtested in accordance with the following pr
12、ocedures. Performball compression test of Test Method F 1888 prior to ball CORtest of Test Method F 1887.5.1.1 Compression350 to 375 lb at 0.25-in. deflection(1557 to 1668 N at 6.4-mm deflection) in accordance with TestMethod F 1888. Balls to be labeled with compression value.5.1.2 Weight6.25 to 6.7
13、5 oz (177.2 to 191.4 g). Balls to belabeled with weight value.5.1.3 Size12.00 to 12.25-in. (304.8 to 311.1-mm) circum-ference. Balls to be labeled with size value.5.1.4 Core MaterialPolyurethane.5.1.5 Ball COR0.450 to 0.470 in accordance with TestMethod F 1887. Balls to be labeled with COR and test
14、speed inft/s.5.2 Bat-Ball COR Test Apparatus:1This test method is under the jurisdiction of ASTM Committee F08 on SportsEquipment and Facilities and is the direct responsibility of Subcommittee F08.26 onBaseball and Softball Equipment.Current edition approved June 1, 2009. Published June 2009. Origi
15、nallyapproved in 1998. Last previous edition approved in 2005 as F 1890 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe
16、 ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2.1 Ball CannonA device capable of shooting a ball ata speed of 88 ft/s. The ball shall not have a spin rate in excessof 10 rpm. Typical pitching machines cannot yield t
17、he aimingaccuracy required by this test method. Cannon exhaust air mustnot cause motion of the bat in the absence of an impact. Theball cannon can be any distance from impact location, as longas it can meet the ball aim requirements and provide six validimpacts in twelve shots or less.5.2.2 Bat Spee
18、d GateAlight trap device, or an equivalent,capable of measuring an edge traveling at speeds of between 5and 15 ft/s with a resolution of one hundredth of 1 ft/s (0.01ft/s) with an accuracy of at least 61 % when the distancebetween the first and second sensor is between 3 in. (76.2 mm)and 3.6 in. (94
19、.1 mm). The first sensor shall trigger when thebat rotates no less than 25 and no more than 30 from its startposition. It is suggested the second trigger be 3 in. (76.2 mm)away from the first and must not be any further than 3.6 in.(91.4 mm) away on a 6-in. (15.24-cm) radius.5.2.3 Ball Speed GateA l
20、ight trap device, or an equiva-lent, capable of measuring a sphere traveling at speeds inexcess of 88 ft/s (26.8 m/s) with an accuracy of 0.5 ft/s (0.2m/s) or better. The device shall measure across a length of noless than half the ball diameter to avoid centering error. Forexample, when testing sof
21、tballs, the device shall sense anobject across a 2.0-in. (50.8-mm) line. The first sensor shalltrigger when the ball is no more than 12 in. (30.5 cm) from thebat surface. The second sensor shall trigger between 3.6 in.(91.4 mm) and 8 in. (203.2 mm) from the first sensor. Thesecond sensor is located
22、between the first sensor and the batsurface.5.2.4 Bat Pivot SupportA turntable, rotating in the hori-zontal plane, with clamps to support and align the bat in thepath of the ball. The clamp surfaces shall be a 45 Vee clampwith a radius no greater than 2.0 in. (50.8 mm). The rotatingclamp and shaft a
23、ssembly shall not weigh more than 6 lb (2.7kg) and shall spin freely via ball bearings (see Fig. 1). Thepolar MOI for the clamp turntable assembly shall not exceed192 oz-in.2(35 117 g-cm2). The actual MOI of the clampturntable assembly shall be determined and used in theperformance calculations.6. C
24、alibration and Standardization6.1 Ball Speed GateThe distances between the sensors ofthe speed gates must be known and recorded to the statedtolerances. The accuracy of the timers used in the velocitysensors must be adequate to provide the stated velocityaccuracy at maximum stated speeds. The timers
25、 used shall becalibrated on at least a yearly basis.6.2 Reference Standards and BlanksA standard bat andball shall be used for reference purposes to verify propermachine operation.7. Conditioning7.1 Ball and Bat Conditioning and Test Room Conditions:7.1.1 Test balls shall be placed in an environment
26、allycontrolled space for at least 14 days immediately beforetesting. Wood bats shall be stored at these environmentalconditions for at least 24 h prior to testing. Non-wood batsshall be stored at these environmental conditions for at least 2h prior to testing.7.1.2 Temperature is to be maintained at
27、 72 6 4F (22 62C).7.1.3 Relative humidity is to be maintained between 40 and60 %.7.1.4 Temperature and relative humidity are to be measuredand recorded hourly within 60.5F (60.3C) and 62%RHover conditioning and test duration.8. Procedure8.1 Determination of Bat Features and Test LocationDetermine ba
28、t balance point (BP), bat MOI, and bat COP inaccordance with Test Method F 2398.8.2 Bat Test Procedure:8.2.1 Ready and calibrate ball and bat speed gates inaccordance with the manufacturers instructions.8.2.2 Select a test ball in accordance with 5.1, and record theactual values of compression, weig
29、ht, size, and COR of the ballin accordance with 5.1.8.2.3 Set ball cannon to fire the ball at the desired impactspeed of 88 ft/s (26.8 m/s). Valid test speeds are considered tobe those within 61 % of the targeted test speed.FIG. 1 Bat Testing MachineF18900928.2.4 Mount bat in the clamps on the bat p
30、ivot support. Thedistal end of the bat knob must be 6 in. (152.4 mm) from theaxis of rotation of the turntable assembly.8.2.5 The ball impact must be centered vertically andhorizontally on the bat diameter at the previously measuredCOP.8.2.6 Position the bat against the start position reference,whic
31、h must place the bat axis perpendicular to the ball line oftravel. (See Fig. 1.)8.2.7 Verify that all speed traps are reset and ready to takedata.8.2.8 Load selected test ball in ball cannon. Attempt to loadtest ball so that its impact with the bat will be between thestitches of the ball.8.2.9 Shoot
32、 the ball at the bat, observing the necessarysafety precautions.8.2.10 Record ball inbound speed and bat rebound speed.Do not use data where the ball inbound speed deviates by morethan the tolerances stated in 8.2.3 from the targeted test speed.8.2.11 Continue testing for six valid impact readings o
33、r fortwelve total impacts. For a given test ball, rotate the ball in thecannon between impacts so that the impact area of the ball isdifferent for each impact. A single test ball may be tested onceon each impact area of the ball with no rest period betweenimpacts. Following this series of up to four
34、 impacts on a singleball, a rest period of at least 10 min following the last impactis required prior to retesting, using the same ball. If six validimpacts are not achieved prior to twelve total impacts, fix theset-up to alleviate cause of invalid impacts. Verify supportsystem for the ball cannon,
35、ball speed gate, and bat pivotsupport are rigid.9. Calculation of Results9.1 Calculate the BBCOR for each valid impact using Eq 1:BBCOR 5S1 1IwR2DSDRtdrTD 1 (1)where:D = distance between bat speed sensors, in. (cm),d = distance between ball speed sensors, in. (cm),I = MOI of bat, oz-in.2(g-cm2),R =
36、COP distance, in. (cm),r = radius to bat speed sensors, in. (cm),T = time for bat to travel through bat speed sensors, s,t = time for ball to travel through ball speed sensors, s, andw = weight of the ball used in each event, oz (g).9.2 CalibrationDetermine the value of the combinations(D/dr) using
37、Eq 2 as follows. Place a large calibration mass(MOI $ 30 000 oz-in.2) in the bat position on the pivotingstage. Measure its MOI and COP in accordance with TestMethod F 2398. Shoot a ball of known COR and weight (w).Measure t and T. Determine (D/dr) from ball COR as follows:Ddr51 1 Ball CORS1 1IwR2DS
38、RtTD(2)9.3 Calculate the BPF for each valid impact using Eq 3:BPF 5BBCORBall COR5SS1 1IwR2DSDdrDSRtTD1DBall COR(3)9.4 Calculate the average BPF for the test bat from the sixvalid impacts using Eq 4. When different balls are used to testthe same bat, always be sure to calculate the BBCOR and BPFusing
39、 the actual size, weight, compression, and COR of the ballused in each of the six valid impacts:BPFavg5BPF!11 BPF!21 . 1 BPF!6!6(4)9.5 Calculate the BBS value of the test bat using Eq 5 and6:k 5SwWD1SwR a!2I Wa2!D(5)BBS 5V1 1 e! 1 ve k!1 1 k!(6)where:V = bat swing speed (mph) at the COP,v = pitch sp
40、eed (mph), the horizontal speed of theball incoming to the batter,W = bat weight, oz,w = weight of ball used in each event, oz (g),I = MOI of bat, oz-in.2(g-cm2),e = BPF 3 (SB COR 4 TB COR),a = distance from pivot to center of mass (balancepoint),R = COP,k = ball-bat inertia ratio,SBCOR = 0.46, andT
41、BCOR = the measured COR of the test ball.10. Report10.1 Report the following information:10.1.1 Name of the test facility and test operator,10.1.2 Test date,10.1.3 Hourly measurements of test conditions, including:10.1.3.1 Humidity and temperature of the ball and batconditioning and test room enviro
42、nments,10.1.3.2 Number of hours ball and bat were in conditioningenvironment.10.1.4 Test equipment used for this test method,10.1.5 Test ball information in accordance with 5.1, includ-ing the compression, weight, size, and COR of the test ball,10.1.6 Bat model, length, weight tested, and any otherp
43、ertinent data, such as condition of the bat or modification tothe bat,10.1.7 Bat MOI and COP, and MOI of the bat pivot support,10.1.8 For each impact (including invalid impacts) ballinbound speed, bat rebound speed, BBCOR, and BPF,10.1.9 Final Average Bat Performance FactorAssumingcurrent ball COR m
44、easurement variations are 60.01, theBBCOR uncertainty is currently 60.02. This results in a BPFuncertainty of 60.05. To reflect this uncertainty, the BPFassigned to each bat will be the measured average BPF reducedby the 0.05 uncertainty. Expected future improvements inmeasurement equipment and prod
45、uct control will reduce theabove uncertainty,F189009310.1.10 Any and all unique observations including, but notexclusively, any damage to the bat or test ball, misdirected ballimpacts, and any odd noises or vibrations, and10.1.11 Calibration certificate numbers for measurementdevices and velocity ti
46、mers.11. Precision and Bias11.1 Precision and bias evaluations have not been conductedfor this test method. When such data are available, a precisionand bias section will be added.12. Keywords12.1 bat performance; BBCOR; BBS; BPF; COR; softballbats; softballsASTM International takes no position resp
47、ecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This s
48、tandard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Interna
49、tional Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM a
