A device which is used to make measurements such as current, resistance and voltage of an electrical circuit is called a multimeter. A major difference between analog and digital multimeter is that the analog multimeter comprises of a continuous scale in which a needle shows the value whereas in the digital multimeters such as Fluke, a digital display directly indicates the value.
In order to take a reading the type of measurement such as current, resistance, or voltage and whether it’s a direct current or an alternating current, the anticipated range needs to be chosen from the large dial below. After that the leads displayed docked on the right are put at the appropriate points on the circuit.
Analog multimeter comprises of a coil that carries current attached to a rotatable drum and two constant magnets are placed on any particular side of the coil. When the current tends to flow across the coil it forms a magnetic field around it. Now this magnetic field tends to interact with the magnetic field of the constant magnet hence the drum rotates whenever the current flowing through the coil tends to change. A particular needle is attached with the drum which has the capability to move along the reading scale. An analog multimeter usually measures current and the measurements of resistance and voltage are first converted to an equivalent current which is then shown by the needle.
In digital multimeter in order to measure resistance and current a part of some internal circuitry is used for converting resistance values and current values to the same voltage values. Voltage can be converted into a digital signal by using an analog to digital converter and a value is shown by using a 7 segment display.
The type of measurement and the range should be selected manually in the old digital multimeters however majority of the new digital multimeters have an auto ranging feature. Digital multimeters as compared to analog meters do not need be calibrated as frequently. Moreover in digital multimeters the readings are way more precise in and no chance exists for parallax errors to take place when taking a reading. When a digital multimeter tends to measure a value that is fluctuating constantly it becomes very complicated to take a reading.
Difference in Display
Generally an analog multimeter uses a continuous scale and needle tends to move along the scale in order to show or indicate a reading.
A Digital multimeter on the contrary generally uses a digital display.
Difference in Operating Mechanism
Analog multimeter generally uses a galvanometer which measures current.
Digital multimeter tends to use an analog to digital converter in order to measure voltage.
Sources of Error
If you take readings from an analog multimeter it may produce some parallax errors.
If you are taking readings from a digital multimeter it is complicated to find an accurate average value when the reading is fluctuating.
You need to calibrate the analog multimeters more often.
There is no need to calibrate the digital multimeters as often as analog multimeters.
If you work in the electrical field, then you must realize how important it is that you can find the right tools that will aid you in doing your job right, you know how risky your line of work is and having the right tools that you can depend on will ensure that you are safe and sound every time you will decide to take on a project. One such tool that you can never go without is the multimeter.
Every electrician out there knows how important it is that they have a device that they can use to tests the presence of current whenever they have to work on circuits and in connecting things together. Whether they need the current to be there or if they have to be sure that there is no current in the circuit, it is always going to be dependent on the multimeter to establish this. So, if you are in the market to find a multimeter for you to use, see to it at least that you find the best there is.