READING AN ELECTRIC METER
An electric meter, which is similar in appearance to a gas meter, consists of three or four dials, which are placed side by side or in the shape of an arc. In the usual type, which is shown in Fig. 2 and which consists of four dials placed side by side, each one of the dials contains
ten spaces and a hand, or indicator, that passes over numbers ranging from to 9 to show the amount of electricity used. The numbers on the dials represent kilowatt-hours
, a term meaning the energy resulting from the activity of 1 kilowatt for 1 hour, or 1 watt, which is the practical unit of electrical power, for 1,000 hours. Since 1,000 hours equal 1 kilowatt, 1,000 watt-hours equal 1 kilowatt-hour.
It will be observed from the accompanying illustration that the dial on the extreme right has the figures reading in a clockwise direction, that is, from right to left, the second one in a counter-clockwise direction, or from left to right, the third one in a clockwise direction, and the fourth one in a counter-clockwise direction; also that above each dial is indicated in figures the number of kilowatt-hours that one complete revolution of the hand of that dial registers.
To read the meter, begin at the right-hand dial and continue to the left until all the dials are read and set the numbers down just as they are read; that is, from right to left. In case the indicator does not point directly to a number, but is somewhere between two numbers, read the number that it is leaving.
For example, in Fig. 2, the indicator in the right-hand dial points to figure 4; therefore, this number should be put down first. In the second dial, the hand lies between and 1, and as it is leaving 0, this number should be read and placed to the left of the first one read, which gives 04. The hand on the third dial points exactly to 6; so 6 should be read for this dial and placed directly before the numbers read for the first and second dials, thus, 604. On the fourth and last dial, the indicator is between 4 and 5; therefore 4,
which is the number it is leaving should be read and used as the first figure in the entire reading, which is 4,604.
After the reading of the electric meter has been ascertained, it is a simple matter to determine the electricity consumed since the last reading and the amount of the bill. For instance, assume that a meter registers the number of kilowatt-hours shown in Fig. 2, or 4,604, and that at the previous reading it registered 4,559. Merely subtract the previous reading from the last one, which will give 45, or the number of kilowatt-hours from which the bill for electricity is computed. If electricity costs 3 cents a kilowatt-hour, which is the price charged in some localities, the bill should come to 45 X .03 or $1.35.