Reading Electric Power Meters


Reading an electric power meter is not hard, and being able to read your power meter can help you keep track of your power consumption. The power used is measured in kilowatt hours. That is the number of watts multiplied by the number of hours. If you were to run a 100 watt bulb for one hour, that would be 0.1 kilowatt hours. Yearly power consumption is shown on some household appliances such as refrigerators. It may say 1000 kilowatt hours, meaning that is the amount of power it consumes in a year.


                   Power Meter
  _____     _____     _____     _____     _____
 /9 0 1\   /1 0 9\   /9 0 1\   /1 0 9\   /9 0 1\
|8     2| |2     8| |8     2| |2     8| |8     2| 
|7     3| |3     7| |7     3| |3     7| |7     3|
 \6_5_4/   \4_5_6/   \6_5_4/   \4_5_6/   \6_5_4/

                 KILOWATT HOURS

Meters usually have 4 or 5 dials, the older ones usually have 4, while the newer have 5. Each of the dials is labeled 0-9, alternating between clockwise and counter clockwise. To read the meter start with the first dial on the left. If the dial is between two numbers, read the smaller number. If the dial is pointing directly to a number, then look at the dial to the right. If the dial on the right is about to pass 0 then read the smaller number. If it has already passed 0 then read the larger number. If the last dial is pointing to a number (there is no dial on the right) you can just say that it is the number the dial is pointing at.

Look at the image of a meter above. Starting with the first dial to the left, we see it is pointing between 3 and 4. You always take the lower number, so the first digit is 3. The next dial is between 5 and 6, so the second digit is 5. The third dial it is pointing at the 8. So we have to look at the dial to the right, and we see that dial has not yet passed 0, so the third digit is 7. The fourth dial is between 0 and 9, so 9 is the forth digit. And the last dial is between 6 and 7, so the last digit is 6. When we put all the digits together we get 35796 kilowatt hours.

If you want to know how many kilowatt hours you used up in a certain time period, simply subtract the current meter reading by the previous. If a few days later we looked at the same meter as above, and it read 35821, then in that time period 25 kilowatt hours were used.


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