1, press down the control rod so that the upper and lower measuring heads are separated and wiped clean.
2, press the key, open the power, check whether the display is normal.
3, check whether it is zero when the head is closed at the upper and bottom, and if it is not the zero button.
4, push down the control rod, so that the upper measuring head has enough distance away from the lower measuring head, and the measured workpiece is placed on the lower measuring head, and then the lever is relaxed, so that the upper measuring head is pressed to the workpiece and read.
5, when required to be displayed in a different mode, the mm/in key can be selected.