develop consensus standards for use by TNI's programs. This group has a support role in assisting other programs with activities such as guidance and standards interpretation.
fosters the generation of data of known and documented quality is through the National Environmental Laboratory Accreditation Program, or NELAP. The purpose of this program is to establish and implement a program for the accreditation of environmental laboratories.
is to establish and maintain a national PT program to support TNI’s National Environmental Laboratory Accreditation Program, and other activities.
Field Activities Program (NEFAP) Executive Committee is to establish and implement an accreditation program for field sampling and measurement organizations (FSMOs).
Audit Sample Program is to develop consensus standards for the manufacture and analysis of audit samples for source emission testing.
on a variety of topics of interest to the environmental measurement community. TNI also hosts two regularly scheduled meetings per year, typically in January and August. Both are a week long and involve open meetings of TNI committees as well as training courses and other special sessions.Combined Interpretations of the 2003, 2009, and 2016 Standards that apply to Volume 1 of the 2016 TNI Standard
Question: We are not sure exactly what this section is requiring of us. What does it mean by "the experimentally observed precision at each testing level"? We are assuming that the simplified version of this section would say that our calculated precision values from our duplicates cannot be greater than the uncertainty of either sample used in the calculation. Is that correct? TNI Response: Section 1.5.4 states specifically that "the experimentally observed precision at each testing level [of the precision evaluation in section 1.5.3] shall not be statistically greater than the maximum combined standard uncertainty of the measurement results at that level, although it may be somewhat less." Section 1.5.3 establishes different approaches for "reference methods" and for laboratory-developed (or modified) methods. For "reference methods", 1.5.3 a) the standard deviation of the results is calculated for at least four spiked samples as described in Section 1.6. The standard deviation of the four replicate results is compared to the calculated combined standard uncertainty for each of the four results. The CSU is acceptable as long as it is equal to or greater than the experimental standard deviation of the four results. 1.5.3 b) addresses non-grandfathered, non-reference methods. It states that the laboratory shall use a documented procedure to evaluate precision and bias. An acceptable approach will determine the standard deviation for at least three blank samples, and at least three replicate samples at each of three known activities that span the range of activities expected from samples to be analyzed using the method. The calculated CSU for each sample result is compared to the standard deviation of results at that activity level and is considered acceptable as long as it is statistically equivalent, or slightly lower. Analysis of duplicate samples will not meet the minimum requirements of either of these two approaches. This section was extensively revised in the 2016 standard. The SIR is obsolete.
MODULE 6: RADIOCHEMICAL TECHNICAL REQUIREMENTS
Section: 1.5.4
