Quality Inspection Flashcards

How should a technician correct a wrong entry in a field book?

Answer: Draw a single line through it so it stays readable and write the correct value nearby

Field notes are legal records, so original entries must stay readable and never be erased.

What is the best independent check of a staked point?

Answer: Measuring to it from a different control point or setup

Checking from a different station is independent of the original setup, backsight, and coordinates.

After setting up a total station and orienting to a backsight, what additional check is recommended?

Answer: Measuring to a second known control point and comparing the result to its published coordinates

A check to a second known point confirms both the setup and the orientation before collecting data.

A set of repeat measurements is tightly grouped but all are offset from the true value. This describes measurements that are:

Answer: Precise but not accurate

Close agreement means high precision, while a consistent offset from truth means poor accuracy, which points to a systematic error.

A steel tape standardized at 68°F is used at 95°F. What is the sign of the temperature correction to the measured distance?

Answer: Positive, because the expanded tape reads too short

The tape lengthens in heat, so it reads less than the true distance and the correction must be added.

What is the sign of the sag correction for a tape suspended between two supports?

Answer: Always negative

A sagging tape follows a curve longer than the straight chord, so measured distances are too long and the correction is negative.

In quality review, a residual larger than about three standard deviations is generally treated as what?

Answer: A likely blunder that should be investigated

Random errors almost never exceed 3σ (about 99.7% fall within it), so such values usually point to mistakes.