CST Repeatability & Linearity Testing 3

Question 1

What effect does temperature change during a repeatability test have on the results?

Accepted Answer

Temperature changes can introduce thermal drift, invalidating the test

Answer

Thermal drift from temperature changes during testing can mask true repeatability errors or create false failures, so tests should be conducted at stable temperatures.

Question 2

A linearity test uses test weights placed at 0%, 25%, 50%, 75%, and 100% of capacity. Which loading sequence is preferred for detecting hysteresis combined with linearity error?

Accepted Answer

Ascending then descending loads

Answer

Testing with both ascending and descending loads reveals both linearity errors and hysteresis, which only appears when comparing loading and unloading paths.

Question 3

On a multi-interval scale (multiple ranges), linearity testing must be performed:

Accepted Answer

Within each weighing interval separately

Answer

Each weighing interval of a multi-interval scale has its own tolerances and must be evaluated independently for linearity compliance.

Question 4

A vehicle scale shows good repeatability at one axle position but poor repeatability when the vehicle is centered on the scale. The most likely cause is:

Accepted Answer

Uneven load distribution across the deck or load cells

Answer

Poor repeatability that varies with load position on a vehicle scale typically indicates uneven load cell response or deck flexion affecting load distribution.

Question 5

The 'corner load test' on a platform scale is most closely related to which scale performance characteristic?

Accepted Answer

Shift (off-center load) error, related to uniformity of response

Answer

Corner load testing evaluates shift error — variation in reading based on where a load is placed — which is related to the uniformity of the scale's spatial response.

(CST) Certified Scale Technicians Practice Test

(CST) Certified Scale Technicians Practice Test

CST Repeatability & Linearity Testing 3