This standard is applicable to products with an accuracy level of 0.0001~0.1 [1ppm~1000ppm (parts per million), 1×10-6~1×10-3 (scientific notation)] DC potentiometer, and suitable for built-in auxiliary equipment of the above potentiometer. This standard does not apply to potentiometers for which zero balance is obtained automatically, for those potentiometers which obtain a partial indication by means of a balance detector scale, or for external auxiliary equipment used with potentiometers.