CST Vehicle Scale Systems & Applications 2

Question 1

What is weigh-in-motion (WIM) technology primarily used for in vehicle weighing applications?

Accepted Answer

Screening or identifying potentially overweight vehicles without requiring them to stop

Answer

Weighing stationary vehicles with higher precision than static scales

Answer

Replacing static truck scales for certified legal-for-trade transactions

Answer

Measuring individual axle loads of parked commercial vehicles

Question 2

What is the primary operational difference between a portable axle scale and a full-platform truck scale?

Accepted Answer

Portable axle scales weigh only individual axles sequentially, while platform scales weigh the entire vehicle simultaneously

Answer

Portable axle scales are more accurate than full-platform scales

Answer

Platform scales measure gross weight only; axle scales measure payload only

Answer

Portable scales use hydraulic load cells; platform scales use electronic strain gauge cells

Question 3

When testing a vehicle scale for repeatability, what is the correct procedure per standard weights and measures practice?

Accepted Answer

Apply the same test load at least three times and verify that all readings fall within the allowable tolerance

Answer

Test at five different positions across the scale deck with varying loads

Answer

Apply the maximum capacity load twice and compare the two readings

Answer

Use a calibrated test truck weighed at different times of day

Question 4

What is the most common cause of rocking or instability in a vehicle scale deck?

Accepted Answer

Improper load cell mounting, unlevel check rods, or uneven foundation support

Answer

Overloading the scale beyond its rated capacity

Answer

Electronic interference from nearby high-voltage equipment

Answer

Using an indicator that is incompatible with the load cell rating

Question 5

What is the function of a check rod (restraint rod) on a vehicle scale deck?

Accepted Answer

A mechanical rod that limits horizontal movement of the deck while allowing free vertical deflection for weighing

Answer

A device that electronically verifies load cell output accuracy

Answer

A calibration reference rod used to establish the zero reference point

Answer

A safety lock that prevents the scale from operating when overloaded

Question 6

What is 'zero drift' in a vehicle scale, and what typically causes it?

Accepted Answer

A gradual shift of the zero reference point caused by temperature changes, load cell fatigue, or foundation settlement

Answer

A display rounding error in the indicator caused by software limitations

Answer

A calibration error introduced by using incorrect test weights during the last calibration

Answer

A communication fault caused by damaged signal cables between load cells and the indicator

Question 7

What is 'shift error' (cornerloading error) in a vehicle scale, and how is it detected?

Accepted Answer

Non-uniform weight response across different areas of the deck; detected by a shift test placing test weights at multiple deck positions

Answer

An error from overloading one end of the deck; detected by maximum capacity test

Answer

An error in the corner digit of the indicator display; detected by comparing display segments

Answer

Mechanical binding at the deck corners; detected by visual inspection of the corner mounts