1. This British Standard specifies the requirements for direct current ratiometer indicators for applications on aircraft such as:
a. the measurement of temperature when the controlling resistance is a temperature-sensitive element wound with nickel or platinum wire;
b. the measurement of pressure when the controlling resistance is varied by means of a pressure-sensitive device connected in the pressure circuit;
c. the measurement of angular or linear displacements when the controlling resistance is varied by the aircraft part, the position of which is to be indicated.