NICET - Highway Construction Inspection Practice Exam

True or False: If the tension is correct when using a steel tape, but there is sag, the measurement is accurate.

1. True

2. False

3. Depends on the length of the tape

4. Only if the terrain is flat

The correct answer is: True

When measuring with a steel tape, it is crucial to understand how tension and sag can influence the accuracy of measurements. Although proper tension is necessary to ensure that the tape is straight and taut, sag occurs when the tape hangs down due to its weight, particularly over longer distances. This sag introduces an error in the measurement because the tape does not follow a perfectly straight line between the endpoints. Thus, if there is sag present, even if the tension is correctly applied, the measurement will not be accurate. This is fundamentally due to the fact that a precise measurement requires the tape to be perfectly straight between the two points being measured. Any deviation from this straight line, such as sag caused by gravity, will create a discrepancy between the actual distance and the measurement recorded. For accurate measurement with a steel tape, both correct tension and the elimination of sag are necessary. Therefore, the statement that if the tension is correct but there is sag, the measurement is accurate, is false.