Have you ever encountered with electrical supply failure at your home or any of your electric appliance went out of power suddenly? Or you are a electronics enthusiast and want to know how to use a multimeter? If you want to diaganose and sort out minor faults at your home or office then this guide is really for you. With little general knowledge you can check outlet,s voltage, any appliance,s amperes and resistance aswell.
This blog can also help you if you are a working electrician and keen of electrical knowledge. Multimeters are most helping tool in electrical and electronics field. Alongwith voltage, current and resistance we can also use them to check diodes, continuity, capacitance, frequency and some more advanced parameters.
First of all we strongly recommend you that if you don,t have electrical background you should first get a proper safety training before using multimeters. As you know it,s a dangerous work of playing with live wires having high and low voltage in them. Without safety measures there would be more chances of getting shock accidently.
Before doing any task with multimeter you should first consider safety and take necessity measures. Make sure that you are not bare footed, without insulation gloves and children are away from you if you are at home. Read multimeter,s manual carefully and try to act upon it completely. This will ensure you and yours meter,s safety.
How to measure voltage?
Voltage test is a most common test people do through multimeters. Voltage is actually a potential difference between any two points of conductor from which electric charge or current is flowing. There are mainly two types of voltage, one is called low voltage and other is high voltage. In low voltage we generaly have 120v and 220v systems in different countries, in three phase 440v systems. High voltages are specific to grids and power houses only.
- First of all turn on your multimeter, put test leads to related sockets. COM or common is a black color test lead which is used only for common or neutral.
- Digital multimeters has separate sockets, one is for voltage and resistance, other is for checking current. So for testing voltage put red lead into voltage socket.
- Now is time to set right switching option. On dial of multimeter switch rotory switch to voltage. If your multimeter is manual range then set range according to voltage level, for example if you are testing volts under 200 set range which under 200 volts.
- In auto range multimeters there,s no need to set range, meter will automatically detect that.
- Now is the time to select points where you will connect multimeter,s probes and get voltage reading. Always select intact and easily accesible connection points, so you can get best accurate readings.
- Be clear about which is neutral point and which is phase in case you are working on single phase system. In three phase you can connect probes to any to two phases to get phase to phase readiings.
- Carefully connect black lead to neutral or common, red to live phase and see results on multimeter lcd.
- Double check the results for more satisfaction.
How to check current through multimeters?
If you have a clamp multimeter then your life is easy, as it,s a best device to check amperes. You only needs to encircle live wire throgh clamp jaw, and you,ll get readings without even making physical contact. Clamp meters works on fradays law of mutual induction, and are so amazing handy devices.
Procedure of testing current through digital multimeter is given below,
- To measure current through DMM you have to break circuit first, don,t forget to turn off power before breaking circuit.
- Set meter,s range to maximum amps which is generally 10A and 20A max in some multimeters.
- Check sockets, test leads should be at right position.
- Now connect test leads to broken wires, it can be done more perfectly by alligator clips otherwise you can aslo do by probes.
- Check readings on multimeter lcd.
How to measure resistance through multimeter?
Resistance is another most common test performed by multimeters. Resistance is actually overall opposition of conductor against flowing charge. Specially ground resistance should be regularly checked to make sure circuit,s safety. Process of testing resistance by multimeter is not much different from voltage and current. Below are some points about procedure of ohm measurements in multimeters.
- First of all check test leads should be in resistance checking socket, generally with this sign Ω .
- Now turn off circuit where you want to measure resistance. Without disconnecting circuit you can,t measure it.
- Now adjust ohmic range from rotory dial switch. Set resistance range more then the magnitude you are going to test for more good sensitivity. For example if you want to measure 1 ohm resistance, set range to 20 ohms.
- Now connect test probes to circuit or element under test and check readings.
Continuity test with Multimeter
Continuity as its name suggests is a general test which tells either the circuit is complete and ready for current flow. It,s just like when a airplane has to be landed on airport, teams monitor if runway is clear?, everything is clear? Then they allow airplane to land on runway. Continuity test is a simple test, assisted by a beep buzz sound which indicates about condition of circuit.
It,s a very beneficial test which allows us to know components health. We can test various equipments like switches, circuit breakers, fuse, wires , motors and almost all other electric circuits and components.
- Firstly, check dial position it should be on continuity or ohm setting.
- Now turn of circuit or device which is under test, also don,t forget to separate it from other components in circuit.
- Some multimeters has a dedicated continuity test button, so press that button.
- Now connect test probes to starting and ending point of circuit or device.
- If multimeter beeps buzz sound that means circuit,s path is complete , otherwise multimeter will not beep.
How to test battery voltage with multimeter?
Dc power means batteries are only source of power at farthest locations. We also see batteries around us everywhere, according to a survey there,s no room no office left in modern world where you can,t find a battery of any type.
To check overall battery health and charge voltage is a primary factor. If you have a little know how to multimeter functionalities you can easily check your battery voltage. Otherwise follow steps described below,
- First of all insert COM or black probe to COM socket and red probe to socket with V or mv option.
- Set meter dial to dc voltage point.
- In manual range multimeters, you also has to set range. Suppose you want to test battery of 12v then set range at minimum of 20v dc.
- Now connect black probe to negative sign on battery and red to positive and check reading on screen.