Calibration of a measuring instrument is
the process of breaking in the instrument when it is new.
the process of putting oil in all the moving parts of the instrument.
comparing and adjusting the instrument’s measurement to get the data that you expect during your experiment.
comparing and adjusting the instrument’s measurement to match a known quantity or another correctly functioning instrument’s measurement.

Calibration of a measuring instrument is comparing and adjusting the instrument’s measurement to match a known quantity or another correctly functioning instrument’s measurement.

Explanation:

The process of obtaining the readings from an instrument and comparing with the sub-standards in the laboratory at several points along the scale of an instrument is called Calibration of a measuring instrument. According to the readings obtained from the instrument, a curve is plotted.

The purpose of Calibration is to evaluate and adjust the precision and accuracy of a measuring instrument. Instrument calibration is needed to eliminate bias in an equipment's readings which covers a range of continuous values.

this would be about 43%