CD 11171 Status Update Barry Verdegan 11 September 2018

Key Developments Second CD 11171 ballot closed Candidate material status SRM 2806d and ISO 11171 round robin prognosis

Second CD Second CD results – will proceed to DIS, unanimous with 11 pages of comments from US and UK, mostly clarifications or editorial 6.4 require that data from at least 2 different samples be obtained for each reported threshold, i.e., 3 samples are analyzed, so ensure that each setting is used for at least 2 of these UK various –state that SRM 2806b cannot be used with the revision C.10 revise to keep current particle concentration limits for high particle concentrations, but for particle concentrations less than 50/mL col. 1 and 2 should be regarded as total counts (not concentration). G.5 rather than reference ISO 11500 dilution procedure, should its text in its entirety be incorporated into ISO 11171? Table 4 consider adding uncertainty calculation to document Table A.1 needs the data to be generated by the round robin Project has been placed on 48 month schedule to buy time

SRM 2806d Candidate Material Status NIST has had IFTS samples for about a month and is analyzing them Accelerated aging test in progress SEM examination for unusual particles APC analysis for counts Statistical analysis of data Until full analysis is done, NIST will not accept the material Methodology for uncertainty analysis of SRM is being worked out

SRM 2806d and ISO 11171 round robin prognosis If current samples are accepted, work should proceed quickly for SRM 2806d Round robin results required to complete certification as consensus standard Earliest the round robin can start is around Thanksgiving Once a candidate material has been accepted, the round robin samples will be sent out and participants will be asked to expedite analysis If round robin starts this calendar year, may be able to complete and have results available for discussion in May in Paris If not, will have to delay meeting until round robin is completed.

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