, L-square is generally used to inspect precision measuring tools; Level 1 is used to inspect precision workpieces; Level 2 is used to inspect general workpieces. (2) before use, check whether each working face and edge are damaged. The left and right sides of the long side of Angle Square and the upper and lower sides of the short side are the workpiece surface (that is, the inner and outer right angles). Clean the ruler working face and the inspected working face. (3) when using, place L-square on the working surface of the workpiece to be tested, and use optical gap method to identify whether the angle of the workpiece is correct. Take it lightly, lean it lightly, and put it lightly to prevent deformation. (4) in order to obtain accurate measurement results, L-square can be turned 180 degrees and measured again, and the arithmetic average of the secondary reading can be taken as its measurement results, which can eliminate the deviation of the angle ruler itself.
