What is "null method"

Zero \Ze"ro\, n.; pl. Zerosor Zeroes. [F. z['e]ro, from Ar.

1. (Arith.) A cipher; nothing; naught.

2. The point from which the graduation of a scale, as of a thermometer, commences.

   Note: Zero in the Centigrade, or Celsius thermometer, and in the R['e]aumur thermometer, is at the point at which water congeals. The zero of the Fahrenheit thermometer is fixed at the point at which the mercury stands when immersed in a mixture of snow and common salt. In Wedgwood's pyrometer, the zero corresponds with 1077[deg] on the Fahrenheit scale. See Illust. of Thermometer.

3. Fig.: The lowest point; the point of exhaustion; as, his patience had nearly reached zero.

   Absolute zero. See under Absolute.

   Zero method (Physics), a method of comparing, or measuring, forces, electric currents, etc., by so opposing them that the pointer of an indicating apparatus, or the needle of a galvanometer, remains at, or is brought to, zero, as contrasted with methods in which the deflection is observed directly; -- called also null method.

   Zero point, the point indicating zero, or the commencement of a scale or reckoning.