Amperage is defined as the amount of electrical current that passes through an electrical component, such as a wire. In particular, the amperage measures the number of electrons that pass from a given point in a certain period of time, taking into account that 1 ampere (or "amp") is equal to 1 coulomb per second. Measuring amperage is an important activity when working with electrical systems, especially to make sure that the wires are not running more current than they can handle. You can measure the amperage with a special instrument called a multimeter or tester.
Steps
Step 1. Always check your multimeter first
Set the function to “ohm”. It should read about 0 when the probes are touched together, and it should read 1 when they are separated. If not, check the batteries.
Step 2. Determine the amperage range for the DMM
A multimeter is a small, portable device that can be used to measure voltage, amperage, and resistance. Each model is set up only to handle a certain amount of current, and this range must be adequate for the electrical system you wish to test. For example, measuring 200 amps with a multimeter rated for 10A will ruin the multimeter's fuse. The supported amperage is printed on the instrument or can be found in the manufacturer's manual.
Step 3. Select the appropriate function on your multimeter
Most multimeters have specific functions for measuring different quantities. To measure the amperage it is necessary to set the AC or DC amperage measurement function, depending on the electrical system being tested. Your system's power source will determine the type of current. For example, the home power grid is AC, while the power of a battery is DC.
Step 4. Set the range on your multimeter
To ensure that your device does not blow the fuse, set the maximum amperage sensitivity well above your expected reading. You can adjust it down if the multimeter reads nothing when docked in your system.
Step 5. Connect the cables to the appropriate sockets
The multimeter should have 2 leads, each with a probe on the end and a plug on the other. Connect the two cables to the corresponding sockets to measure the amperage; the user manual will specify the correct terminals, if they are not clearly labeled.
Step 6. Activate the circuit through the multimeter to measure the current
This is extremely dangerous and can cause electric shock if you measure your home network or other networks. Turn off all switches before working with the multimeter and use a probe to check that the AC current is not flowing, before touching any wires, especially if they are bare. Do not work in a humid environment or in the presence of water, which can conduct electricity and harm you. Wear heavy rubber gloves. Additional precautions may be needed. Consult an electrical maintenance text (not an online source) before attempting this measurement. Be aware that the wires may not be insulated due to accidental damage during installation or because they are frayed. Lack of insulation can cause electric shock. Someone with a cell phone should always be with you: they won't have to touch you, but they can call an emergency number if needed. This person should also be trained in first aid and resuscitation. In the event of an electric shock, you should be able to move around using insulating material (for example a dry piece of clothing or other), to avoid being shocked in turn due to the conductivity of the skin and perhaps some clothing (and other materials). Consult a book on electrical safety beforehand to also know how to prevent dangers. Squeeze the wire in one place and remove the insulation from both free ends. Secure these ends separately to the amperage tester leads. Complete the measurement only after the cables are properly connected to the amperage tester probes. Make sure these wires, especially the loose ends, can't touch you. Turn the switch back on and adjust the sensitivity of the multimeter if no reading is produced.
Step 7. Turn off the switch and use an amperage probe to make sure there is no power, and only then wire the circuit again
Follow the precautions described in step 5 and those read in the safety text. After taking the reading you still need to reset the broken circuit. It is much safer to buy new thread and replace it than to try to patch up the area where you cut it.
Advice
- Wear heavy rubber gloves when working with live circuits.
- Always read the user manual to follow necessary safety practices before working with the multimeter.
Warnings
- Electricity can cause electric shock and even death.
- Be careful to wear leather or other materials that can conduct electricity.
- Do not work in a humid environment or in the presence of water: it can conduct electricity and cause you serious damage.
- Ask for the availability of a person with a mobile phone so they can help you in an emergency. Check that your cell phone is charged and receiving a signal before going to work. This person should also be trained in first aid and resuscitation. Don't let this person touch you while you work on the circuit.
- Always read a text about electricity (not an online source) before working with any voltage or current source (particularly high ones).
- Wear heavy rubber gloves when working with live circuits.
- Always read the user manual to follow necessary safety practices before working with a multimeter.
