CWT Measurement Standards & Accuracy 4

Question 1

What is 'buoyancy correction' in precision weighing?

Accepted Answer

Adjusting for the upward force of air on the weight and sample

Answer

Buoyancy correction accounts for the upward force of air displaced by the weight and the object being weighed, significant in high-precision applications.

Question 2

A technician notices that a scale's zero indicator drifts slowly upward over 30 minutes with no load. This is most likely caused by:

Accepted Answer

Thermal warm-up of the electronic components

Answer

Electronic components, especially load cells and amplifiers, require a warm-up period; zero drift during this time is a common and expected phenomenon.

Question 3

Under NIST Handbook 44, a 'division' (d) and a 'verification scale interval' (e) may differ. What does a larger 'e' value relative to 'd' indicate?

Accepted Answer

The scale has enhanced display resolution beyond its verified accuracy

Answer

When e > d, the display shows finer increments than the verified accuracy class requires, meaning displayed resolution exceeds verified accuracy.

Question 4

Which test specifically verifies that a scale's reading does not change when the load is shifted from one side of the platform to another?

Accepted Answer

Shift or eccentric load test

Answer

The shift or eccentric load test places the same weight at different positions on the platform to check for position-dependent reading errors.

Question 5

What is the primary purpose of NCWM's Publication 14?

Accepted Answer

Establishing requirements for net-content labeling in commercial transactions

Answer

NCWM Publication 14 provides guidelines and test procedures for checking net contents of packaged goods in commerce.

(CWT) Certified Weighing Technician Practice Test

(CWT) Certified Weighing Technician Practice Test

CWT Measurement Standards & Accuracy 4