Do you frequently find that you need to measure ohms, volts and amps? Frequent users would do best to purchase a digital multimeter for this purpose. This type of meter differs from an analog multimeter in that is comes with a digital LED display. Analog versions make use of a gauge and needle. When you use the digital variety of this tool, your measurements will be more accurate and these devices often come with more features. No matter which type of multimeter you choose to go with, whether it be a range multimeter, an analog multimeter or a digital one, all will measure these three basic currents.
When you go to purchase a digital multimeter or DMM, the first thing you need to look at is the impedance or operating resistance. When the multimeter is introduced into the circuit being tested, it will affect the circuit's current which is why this specification is so important. In addition, you should look at the range of the multimeter. No matter what current you are testing, in order to get an accurate measurement, you must have the proper range for the measurement. When testing a 12-volt battery, a DMM with a 0-25 range setting will be more accurate than one with a 0-500 range setting. Many of these devices come with an automatic range feature. A device with this feature looks at the circuit being tested and automatically sets the proper range. All you will be required to do is set the DMM for the current you are testing.
When choosing your digital multimeter, you will also need to look at the maximum reading capacity. This will give you the maximum amount of current that you can measure using the device. Many digital multimeters have a limit of 10 amps and this will be printed on the front of the device. If you try to measure a higher current using the device, an internal fuse will pop. This prevents the device from being damaged. You cannot increase the maximum reading capacity of a DMM by installing a bigger fuse either. This will just burn it out completely.
Each digital multimeter has to be set up before taking measurements. As this does vary from device to device, you will need to read the instruction manual to ensure you set the device correctly. Buttons may need to be pushed in a certain sequence before you attach the leads and things of that nature. A battery will be needed in order for the device to operate and the instruction manual will provide this information also.