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Standard Interpretation

Standard: 2009 TNI
Section: V1M1, Section 4.2.1 (a)


Please clarify the use of "analysis date" in V1M1, section 4.2.1 a) for successive PT samples. The standard states that the analysis date is to be at least 5 months apart and no longer than 7 months apart. TNI defines "analysis date" as the "calendar date of analysis" in the "Terms and Definitions" section. So, if a PT sample is analyzed on March 15, 2011, is the period anytime between August 2011 and October 2011 (5 - 7 months) acceptable, or, must one use the period August 15, 2011 to October 15, 2011 for the next PT sample?


(PT Expert Committee and NELAP AC, 2-24-14)

The term "analysis date" is as defined in the Terms and Definitions. The 5 to 7 month window would be as is described above; PTs must be analyzed between August 15, 2011 to October 15, 2011 for evaluation purposes.