Question

If the $zer{o}^{th}$ division of head scale is above the index line of pitch scale, then error is said to be

• A. Negative
• B. Positive
• C. Neutral
• D. Bore

Answer 1

The correct option is A Negative

First, take the screw gauge and move it in decreasing order along the index line until it gets tight.At that point, if there is an error in the Screw gauge, we can find there because if there is any error the zero on the head (rotating ) scale does not coincide with the index line when the head scale edge is sharply at the zero of the pitch scale.If the zero of the head scale is above the index line then the error is negative, if the zero is below the index line then the error is positive.