A voltmeter is a device that measures the electro-motive force, also known as voltage. It allows you to measure the voltage in a circuit.
An ammeter, on the other hand, measures the electric current in amperes. Voltmeters and ammeters are connected differently. You can't simply connect an ammeter to the same position that you would connect a voltmeter because it will only bring a huge rush of current that can bring great damage to a circuit breaker. You have to understand that an ammeter has a very low resistance, while voltmeters have very high resistance. An ammeter has a coil with a large wire with only a few turns, while the voltmeter has a coil wound with thousands of turns. That being said, ammeters are connected in series, while voltmeters are connected in parallel. So, it really takes knowledge and skill in order to combine or connect the two together. If you'd like to learn how to connect an ammeter and voltmeter together, continue reading below.
Step 1 – Decide on the Load
Which appliance would you like to test? Is it a lamp, a resistor, a radio or TV? It's best to start with a small and simple item, such as a resistor. Always remember to not hold the resistor terminals when you are measuring it because hand to hand resistance can interrupt the measurement.
Step 2 – Connect the Ammeter and Power Source
Now, take the power source, such as the battery, and connect the positive to one end of the terminal strip or load, such as the resistor. Now connect the negative terminal of the battery to the ammeter's ground terminal labeled as “com”. Next, connect the positive terminal of the ammeter, which is usually the red wire, to the other end of the terminal strip or the other end of the load, in this case the other end of the resistor. Now you have an ammeter connected in series in a circuit.
Step 4 – Connect the Voltmeter
Now, it's time to connect the voltmeter to the ammeter and the rest of the objects in a circuit. Take the black wire, or negative terminal, of the voltmeter and connect it to the negative terminal of the strip or resistor. Take the red wire, or positive terminal, of the voltmeter and connect it to the positive terminal of the terminal strip or the positive end of the resistor where the positive terminal of the battery is also connected.
Now your voltmeter and ammeter are connected. Make sure that the settings for your ammeter and voltmeter are the same when you connect them. This means that if you are using a direct current (DC) power source such as a battery, the setting in both your voltmeter and ammeter should be in DC setting. If you connect it to the power in your plug, which is AC, the settings in the meters should be in AC as well.