CST Analog & Digital Scale Technology 3

Question 1

According to NIST Handbook 44, what is the maximum number of scale divisions (n) allowed for a Class III commercial scale?

Accepted Answer

10,000

Answer

NIST Handbook 44 allows Class III scales a maximum of 10,000 scale intervals (n), balancing resolution with accuracy requirements for commercial use.

Question 2

In analog dial scales, the term 'graduation' refers to:

Accepted Answer

Individual marks on the dial face representing weight increments

Answer

A graduation is each individual division mark on the scale dial or chart, with the interval value defining the smallest readable increment.

Question 3

Which test is used to detect a digital scale's ability to return to zero after a load is removed?

Accepted Answer

Return-to-zero test

Answer

The return-to-zero test verifies that after removing a test load, the indicator reading returns to the same zero reference within tolerance.

Question 4

A spring scale reads 4.95 lb when a certified 5.00 lb test weight is applied. The error expressed as a percentage of the applied load is:

Accepted Answer

−1.0%

Answer

Error = (4.95 − 5.00) / 5.00 × 100 = −1.0%, meaning the scale under-reads by 1%.

Question 5

What is the function of an analog-to-digital converter (ADC) in a digital weighing indicator?

Accepted Answer

Converts the continuous millivolt signal from the load cell to a digital numeric value

Answer

The ADC samples the analog mV/V load cell signal and converts it to a digital number that the microprocessor can process and display as a weight.

(CST) Certified Scale Technicians Practice Test