Question

How do you distinguish positive or negative zero error in screw gauge?

Answer 1

1.if the zero mark on the circular scale is below the line of graduation of the main scale, when yeh gap between stud and flat end is reduced to zero this zero error is called positive zero error .
2.It the zero mark on the circular scale is above the line of graduation of the main scale, when the gap between stud and flat end is reduced to zero this zero error is called as negative zero error.

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