set up of the apparatus is arranged in circuit.ES is the standard e.m.f and Rs is the standard resistance of a cell.K1 is connected to position 1 and K2 closed.The approximation balance length is located.The jockey is tapped along a uniform wire until the G shows no deflection.K2 is then switch on the balance length is located accurately.The length ls is measured and recorded together with the ammeter. The procedure is repeated
Calibration refers to the process of determining the relation between the output (or response) of a measuring instrument and the value of the input quantity or attribute, a measurement standard. In non-specialized use, calibration is often regarded as including the process of adjusting the output or indication on a measurement instrument to agree with value of the applied standard, within a specified accuracy. For example, a thermometer could be calibrated so the error of indication or the correction is determined, and adjusted (e.g. via calibration constants) so that it shows the true temperature in Celsius at specific points on the scale. Calibration also can refer to judgments made by a prognosticator, for example, a weather-forecaster who states that "there is an 80% chance of rain today," if properly calibrated, will say this on precisely 80% of the days during which it rains.