CWT Measurement Standards & Accuracy 3

Question 1

Under NIST Handbook 44, what is the 'acceptance tolerance' compared to the 'maintenance tolerance'?

Accepted Answer

Acceptance tolerance is tighter and applies to newly installed scales

Answer

Acceptance tolerances are tighter and apply when a device is first put into service; maintenance tolerances are more lenient for devices already in use.

Question 2

What is the purpose of a 'sensitivity test' on a mechanical beam scale?

Accepted Answer

To determine the smallest weight increment that causes a visible change in balance

Answer

A sensitivity test determines the minimum additional weight that causes a detectable movement of the beam, indicating the scale's resolution.

Question 3

What does 'eccentricity error' (also called 'off-center loading error') measure?

Accepted Answer

Error caused by placing the load off-center on the platform

Answer

Eccentricity error is the difference in readings when the same load is placed at different positions on the weighing platform.

Question 4

Which OIML class of weights has the most stringent tolerances?

Accepted Answer

E1

Answer

OIML E1 weights have the most stringent tolerances and are used as primary reference standards.

Question 5

A scale displays '±1d' as its division value. If d = 0.01 lb, what is the maximum permissible error for a Class III scale at mid-range?

Accepted Answer

It depends on the specific load applied

Answer

Under NIST Handbook 44, the MPE for Class III scales depends on the number of scale divisions at the applied load, so the specific load must be known.

(CWT) Certified Weighing Technician Practice Test

(CWT) Certified Weighing Technician Practice Test

CWT Measurement Standards & Accuracy 3