1)  Error of a physical measure:    It is the difference between the nominal value and the conventional true value reproduced by the physical measure.

2)  Error of a measuring mechanism:   It is the difference between the value indicated by the measuring mechanism and the conventional true value of the measured quantity.

3)  Zero error: It is the indication of a measuring instrument for the zero value of the quantity measured.

4)  Calibration error of a physical measure:  It is the difference between the conventional true value reproduced by the physical measure and the nominal value of that measure.

5)  Complementary error of a measuring instrument:  It is the error of     a measuring instrument arising from the fact that the values of the influence quantities are different from those corresponding to the reference conditions.

6)   Error of indication of a measuring instrument:   It is the difference between the measured values of a quantity, when an influence quantity takes successively two specified values, without changing the quantity measured.

7)   Error due to temperature:   It  is the error arising  from the fact  that the temperature of instrument does not maintain its reference value.

8)   Error due to friction:   It is the error due to the friction between the moving parts of the measuring instruments.

9)  Error due to inertia:  It is the error due to the inertia (mechanical, thermal or otherwise) of the parts of the measuring instrument.