An ammeter has a meter scale range of 0-1 ampere and 1000 milliamperes with a range of 0-1000 milliamperes. fraction of seldom used in electricity so that, on the 0-1 ampere range, meter reading of 1\2 ampere is given as 0.5 ampere or 500 milliamperes. for less than 1 amperes, millimeters and microammeters are used to measure current. if you are using current between 1 milliampere to 1000 milliamperes of the correct range are used, a very small current of 1 micrometer or less is measured spacial laboratory type instruments called galvanometers.

Since a current is used in electrical equipment are between 100 microammeters and 100 amperes and thus can be measured with a micrometer and milliammeter or ammeters of the correct range. meter scale range for millimeters and microammeters like ammeters are in multiples of 5 or 10 since these multiple are easily changed to other units. 

In using a meter to measure current, the maximum reading of the meter range should always be higher than the maximum current to be measured. a safe method of current measurement is to start with a meter having a range much greater than you expected to measure, in order to determine the correct meter to use.

How Meter Scale Are Reading:-

When you work electrically it is necessary that you take an accurate meter reading, to determine whether the equipment is working properly, and to discover what is wrong with equipment that is not operating correctly. many factors can cause meter reading incorrectly and it is necessary to keep them in mind whenever you used a meter.

you will find to the unable range of a meter scale does not include the extreme end of the reading scale. for nearly all meters, the most accurate reading are those taken near the center of the scale. when current is measured with an ammeter, millimeter, or microammeter, the range of the meter used should be chosen to give a reading as near to mid-scale as possible.

 A zero set adjustment on the front of the meters is used to set the meter at zero on the scale when the current is not flowing. this adjustment is made with a small screwdriver and should be checked when using a meter, particularly if the vertical or horizontal position of the meter is changed. meter scale is used to measure current bare divided into equal divisions, usually with a total of between 30 and 50 divisions.