CWT Measurement Standards & Accuracy 2

Question 1

What does the term 'traceability' mean in the context of weighing standards?

Accepted Answer

An unbroken chain of comparisons linking measurements to national or international standards

Answer

Traceability means an unbroken chain of documented comparisons connecting a measurement back to a recognized national or international standard.

Question 2

Which organization maintains the primary mass standards for the United States?

Accepted Answer

NIST

Answer

NIST (National Institute of Standards and Technology) maintains the primary mass standards for the United States.

Question 3

A scale that consistently reads 0.5 lb high on every load has which type of error?

Accepted Answer

Systematic error

Answer

A consistent offset in one direction is a systematic error, often correctable through calibration adjustment.

Question 4

What is the tolerance for an ASTM Class 4 weight used in commercial weighing?

Accepted Answer

Looser than Class 1 but tighter than Class 7

Answer

ASTM weight classes are numbered 1 through 7, with Class 1 being most precise; Class 4 falls in the middle range.

Question 5

When performing a linearity test on a scale, what is the technician evaluating?

Accepted Answer

Whether accuracy is consistent across the entire weighing range

Answer

A linearity test checks that the scale maintains acceptable accuracy at multiple points across its full capacity, not just at one load.

(CWT) Certified Weighing Technician Practice Test