Meters

—The supply of electric current to consumers is measured by meters, of which there are several types, such as, integrating, chemical, motor and retarded clock meters. An integrating meter consists of a clock which drives a counting apparatus through an intermediate gear operated by the current. The principle of a chemical meter is that the current or a known fraction of it pa es through an electrolytic cell and deposits copper in some types and di olves zinc in others. The chemical action depends on the ampere hours, In a motor meter, the current pa es through the armature of a small motor which has a constant field. The speed of the motor is controlled by fluid friction and is proportional to the intensity of the current. A suitable counting gear attached to the motor indicates the ampere hours, A retarded clock meter operates by the action of the current on the clock movement. The current flows under a magnetic pendulum bob. An force thus added or subtracted from gravity will cause the clock to gain or lose.