Suppose that a standard bourdon tube pressure gauge has a scale of 0 to 1000 psig. If the accuracy of the gauge is plus or minus .5% of the span, what would the range of measured pressure be if the gauge indicates 690 psig?

Correct Answer: Option C — 685 to 695 psig

Accuracy is calculated as 0.5% of the 1000 psig span, equaling 5 psig. At a reading of 690 psig, the potential error range is plus or minus 5 psig. Therefore, the measured pressure range is 685 to 695 psig, accounting for the gauge's specified tolerance over its full scale.