Outline of steps to be followed in the evaluation of uncertainty
involving several secondary quantities

B.  Reported value involves more than one quantity.
 Write down the equation showing the relationship between
the quantities.
 If the measurement result can be replicated directly,
regardless of the number of secondary quantities in the
individual repetitions, treat the uncertainty evaluation as
in (A.1) to (A.5) above, being sure to evaluate all sources of
random error in the process.
 If the measurement result cannot be replicated directly,
treat each measurement quantity as in (A.1) and (A.2) and:
 Compute a standard deviation for each measurement
quantity.
 Combine the standard deviations for the individual
quantities into a standard deviation for the reported
result via propagation of error.
 Compute a standard deviation for each type
B component of uncertainty.
 Combine type A and type B standard deviations into a
standard uncertainty for the reported
result.
 Compute an expanded uncertainty.
 Compare the uncerainty derived by propagation of error with the
uncertainty derived by data analysis techniques.
