The system of the bimetal current meter consists of two bimetal spirals that are installed to work mutually. One bimetal spiral works current-driven, the other bimetal spiral compensates mutually working the ambient temperature, which can vary from -25 °C to +55 °C. A black pointer is coupled to this measuring system, which drags along a red pointer. This red pointer remains at the maximum value reached. The instrument also has a moving-iron movement for instantaneous value indication. The overload of the bimetal scale is 20 % and that of the moving iron is 100 %.