CCT Measurement Uncertainty & Error Analysis

Question 1

What does 'measurement uncertainty' represent in calibration?

Accepted Answer

A parameter characterizing the dispersion of values that could reasonably be attributed to the measurand

Answer

Measurement uncertainty is a parameter that characterizes the range of values within which the true value is estimated to lie, reflecting the doubt about the measurement result.

Question 2

Type A evaluation of measurement uncertainty is based on:

Accepted Answer

Statistical analysis of repeated measurement observations

Answer

Type A uncertainty evaluation uses statistical methods applied to a series of repeated measurements to estimate the standard deviation and standard uncertainty.

Question 3

Type B evaluation of measurement uncertainty is characterized by:

Accepted Answer

Information from sources other than repeated observations, such as certificates and specifications

Answer

Type B uncertainty evaluation uses information such as calibration certificates, manufacturer specifications, reference data, and expert judgment rather than statistical analysis of repeated measurements.

Question 4

The combined standard uncertainty (uc) is calculated from individual uncertainty components by:

Accepted Answer

Taking the square root of the sum of the squares of individual standard uncertainties

Answer

Combined standard uncertainty is obtained by the root sum of squares (RSS) method, which combines individual uncertainty components assuming they are uncorrelated.

Question 5

A coverage factor of k=2 applied to the combined standard uncertainty typically corresponds to a confidence level of approximately:

Accepted Answer

95%

Answer

For a normal distribution, a coverage factor k=2 yields an expanded uncertainty that encompasses approximately 95% of the distribution of values.

(CCT) Certified Calibration Technician Practice Test

(CCT) Certified Calibration Technician Practice Test

CCT Measurement Uncertainty & Error Analysis