Gently remove the caliper, the digital caliper is a high-precision instrument to avoid damage caused by the caliper falling or expanding. Check that the calipers are closed, slide the calipers to check for smooth sliding.

Turn on the caliper switch, there are generally three buttons on the caliper, "unit", "on/off" and "zero" correspond to "mm/inch", "off/on" and "zero" respectively. Press the OFF/ON switch once. The numerical value will now be displayed on the digital display screen. The displayed value is normal.

To reset the caliper, when the displayed value is incorrect, close the caliper and press the "Zero" button to reset the value to zero.

Measure the object demonstration (outer diameter), hold the measured object in the left hand, take the digital caliper in the right hand, pull the caliper, align the caliper with the measurement part, slowly lock the caliper, and the digital display screen will display the size of the object.

Measure object demonstration (inner diameter). Select a grooved object and use the top of the digital caliper to measure. Pull open the caliper, align the caliper with the measurement part, slowly lock the caliper, and the digital display screen will display the inner diameter of the object.