A multimeter, also known as an LCR Meter is one of the most basic tools that students, teachers and engineers use when dealing with electricity or wiring that carries electrical current. How to use a multimeter or LCR Meter is a good question and this this article will help you uncover the answer.
How to Use a Multimeter Properly
Multimeters can do several different types of measurements. They can test for voltage, also known as potential difference. Multimeters can also check for something called continuity. This is important because it detects broken or incomplete circuits. Additionally, multimeters can measure the resistance of a circuit to the flow of an electrical current. The inverse of resistance is an expression of how easy a circuit conducts electricity, and is called conductivity.
When measuring voltages multimeters measure alternating current (AD) and direct current (DC). Your home uses alternating current, your car uses direct current. Multimeters can be analog or digital in nature. Digital models give readouts on an LED, designed to display data to a set precision. Analog meters have a sweep needle that moves over scales which are calibrated.
When testing for Voltage set the meter for either DC or AC voltage. You will need to set the meter for a value within a range you expect the reading to be. If you have no idea or the voltage is unknown, set the meter on the highest range. Then as you take test measurements, work your way down the scales till you reach the correct range. This procedure protects the electronics in the meter from damage due to overload.
To continue testing for voltage touch the negative point probe to a known ground. In a car this would be the car chassis. Then touch the positive point probe to the wire you are testing. The ground point must be on metal that is not covered with paint or other coating. The reading on the meter will tell you what voltage is in the circuit.
If a circuit lets current flow, it has continuity and is considered a closed circuit. A circuit that will not allow current to flow is said to be open. An open circuit can be the result of a break in the circuitry or it can be due to extremely high resistance. Using the multimeter to test for continuity can indicate if the circuit being tested is closed, and usable, or open and not usable.
To test for continuity first make sure you disconnect any power to the meter. You can damage or destroy the meter if you test for continuity while a voltage is connected to the meter. Then select the resistance mode on the meter, at the lowest setting. Some meters have auto zero, for others you must dial the meter to the zero point, while holding the two probe points together. The zero designates no resistance and thus a closed circuit. Then touch the two probes across the circuit you wish to test for continuity.
Resistance of a circuit to the electrical current flow is measured in ohms. Simple test two points in a circuit with the two probes and read the meter to get the resistivity in ohms. You may need to adjust the scale to make an accurate reading.
As long as you are careful your multimeter can give you many years of good service. Test the information in this article with your multimeter so that you are sure you know how to use a multimeter.
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