Calculate the standard error of the accepted reference
value (SEARV) by dividing the CEU by the coverage factor, k,
listed on the supplier’s label or included documentation.
SEARV 5 CEUARV
k (A4.1)
NOTE A4.3—Standard Error (SEARV) is equivalent to Combined Stan-
dard Uncertainty (UC). See NIST Technical Note 1297.
A4.3.1 If the coverage factor, k, is not known, use the value
2.
A4.4 Construct the acceptable tolerance zone:
TZ 5 61.44 =σsite
2 1SEARV
2 (A4.2)
A4.5 Worked out example for kinematic viscosity zone
(band):
σsite 5 0.19 % ~default value from A4.1.1! (A4.3)
CEUARV 5 0.22 % ~from the CVRS label or documentation!