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r� ASTh 01709 testing in accordance with 8.1. If desired. carry -hes 10. then stop testing out a slippage check as described in 8.2 at some to-S) real; point during the course of testing. 10. ctilculations 11.3 Measure and record the average thick- to. on the data record-calculation form ness of the test specimens in the area of impact .0001 in.). 2) record under na the total number of the nearest 0.0025 mm (0 (See fig. - counting only the to select a missile V*S at each missile weight. 11.4 For a starting point. .lost to iCs during test- weight near the expected impact failure weight- TE I--if. during test after 20 drops. IV < 10 Or number of incremental so only 10 Xs after testing is Add the necessary put the locking S . to there will be r > to after 20 drops will it be weights onto the dart shaft and p ,,,Jet�• only where A of the earlier X results. collar into place so that the weights are held ,,C$SarY to Omit some integers 0. 1. 2. etc. for securely in Place- st specimen over the lo.,) Under j, enter - lowest missile 11.5 Place the first te entry. Enter 0 for the each III . . entered. a bottom part of the clamp. making sure that itis %eight at which an ris value has been uniformly flat. free of folds, and that it covers for or next higher missile weightp. ctc. the gasket at all points. Clamp in place with the I 10.3 (,rider . in,, enter the product of i . times top part of the annular clamp. ni•the electromagnet and put the 11) 4 Add the n,*s and enter as N: by the 11.6 Energize -emagnet to re described. NA. Enter will always W,.btehe missile release 10. Add dart intothe podart.nif thendartzsitio. Dc ergl; procedure s bounces offthe the in,'s and enter a s assigned. specimen surface, catch the dart after it t to which an i value of zero i es to prevent,both multiP le impactto wthe ith %eigh missile weight incre- bounc e Enter % W the uniform mi the specimen surface and damag merit employed. failure weight Wr. hempherical contact surface of the dart re- 10.5 Calculate the impact sultinisg from impact with metal parts of the as follows: 1/2)] apparatus. W, - W. 11.7 Test a total of ten specimens at the kLirERNATIVE TESTING TECHNIQUE selected starting missile weight. Record the missile weight and the percentage of failures. 1. Procedure 11.8 If the failure result for the first group of ve groups Of is 0 or too %, increase or de 11. 1 By this technique. success' ten specimens missile weight by 15 g or more for ten specimens each are tested. For each group. crease the miss Method B and one missile weight is employed and from group ,Method A or 45 g or more for ) group missile weight is varied in uniform test another ten specimens as described above to point where Continue in this manner until a failure result increments. Testing is carried to a too % is obtained. Continue there are at least rive results for percentage between 0 and cic result. one too Tc result and at testing groups of ten specimens. varying the failure: one 0 by the selected least three results between 0 % and 100 missile weight between tests . . ng —in quality control work, one may rind it uniform increment, until results encompassing NOTE 2 WF from fewer than five failure the entire range from 0 to too cic failure inclu- useful to estimate necessarily uniformly results at missile weights not n obtained. ipaced.. Of these, no result should be 0 % or 100 % sive have bee -sting. it is suggested less than 50 NOTE 3—For efficiencv in testing. e result should be selected initially be failure. at least on greater than 50 that the missile weight increment and at least one result should be grc. ng averages-of- relatively large so that 0 cle and 100 'c failure results. Either the individual results Or move two are plotted on probability paper (see 12.4). a will be found after testing only two or three groups 01 itraiaht line is fitted and W, is read from the plot. specimens. *'Fill-in" results between the correspond- Values of We estimated in this manner will be ng extremes of missile weight then be obtained in unbiased but will not be as precise as values derived subsequent testing. from at least five failure results employing uniform if the minimum rive missile weight increments as described above. 11.9 At this stage, results described in 11.1 have been obtained. 11.2 Select Method A or Method BT or use. testing is complete- If not. select a new missile as desired, or as required by the elevant ent less than that employed ini- material specification. Set up the apparatus for weight increment 91