CST Repeatability & Linearity Testing 2

Question 1

When performing a repeatability test, the test load should be applied and removed how many times according to NIST HB 44?

Accepted Answer

5 times minimum

Answer

NIST HB 44 requires a minimum of 5 repeated load applications to properly evaluate repeatability error.

Question 2

A scale tested for linearity shows increasing error as load increases. This pattern is best described as:

Accepted Answer

Progressive nonlinearity

Answer

Progressive nonlinearity describes errors that systematically increase or change in magnitude across the measurement range.

Question 3

Which of the following best defines the 'best straight line' method used in linearity analysis?

Accepted Answer

The line that minimizes the maximum deviation of any data point

Answer

The best straight line minimizes the maximum deviation (peak error) between actual scale output and the ideal reference line.

Question 4

During a linearity test on a 500 lb capacity scale, readings at 100, 200, 300, and 400 lb are all within tolerance, but the 250 lb reading is out of tolerance. This indicates:

Accepted Answer

A mid-range nonlinearity

Answer

An out-of-tolerance reading at a mid-range point while endpoints are correct indicates a mid-range nonlinearity in the load cell or mechanism.

Question 5

Repeatability testing on a conveyor belt scale should be performed at what percentage of the scale's maximum capacity?

Accepted Answer

At least 50% of max capacity

Answer

Conveyor belt scale repeatability tests are typically conducted at loads of at least 50% of maximum capacity to produce meaningful results.

(CST) Certified Scale Technicians Practice Test

(CST) Certified Scale Technicians Practice Test

CST Repeatability & Linearity Testing 2