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).
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.Standard Interpretation
Standard: 2016
Section: V1M4, Section 1.7.1.1 (k)(ii)(a)
REQUEST:
V1M4: 1.7.1.1.k.ii.a states, "Measurement of the Relative Error: This calculation shall be performed for 2 calibration levels: the standard at or near the mid-point of the initial calibration and the standard at the lowest level."
Question: What is the correct determination of what "near the mid-point of the initial calibration" means? Does this mean it is half-way between the lowest concentration and highest concentration standards? Does it mean that it is one of the middle calibration points? For example: ICAL standards of 0.5, 1, 5, 10, 25, 50, 100 ug/L. What is "near the mid-point" in this example? Do we use 50, because it’s the concentration that is half-way between the highest and lowest ICAL concentrations or can we use 5 or 10 or 25 because it’s one of the concentrations at the middle of our calibration points?
TNI FINAL RESPONSE:
Since the Standard does not define the level associated with "at or near the mid-point of the initial calibration" either interpretation would be acceptable.