1. 校定，校准，调节(计量器具)
If you calibrate an instrument or tool, you mark or adjust it so that you can use it to measure something accurately.

1. make fine adjustments or divide into marked intervals for optimal measuring

e.g. calibrate an instrument
graduate a cylinder

Synonym: graduatefine-tune

2. measure the caliber of

e.g. calibrate a gun

3. mark (the scale of a measuring instrument) so that it can be read in the desired units

e.g. he calibrated the thermometer for the Celsius scale