A multimeter or a multitester also named a VOM (volt-ohm meter), is an electronic measuring equipment that combines several measurement functions in one way.
It is mainly used to measure the voltage, current (ampere), and resistance. Multimeters are available in two versions like analog and digital. For getting more accuracy, it is better to choose a digital one.
Working principles of multimeter:
In a typical multimeter, the input signal is ac or dc of voltage, current, temperature or any other parameter that basically converted to dc voltage within a range of the ADC. Then the analog to a digital converter converts dc voltage into its equivalent digital numbers which are displayed on the multimeter screen.
This article explains how to takes a reading for current, voltage and resistance with a multimeter. Before that, you need to clear with basic parts of a multimeter.
Basic parts of multimeter:
- Selection knob: this select what you want to measure whether current, voltage or resistance.
- Display: It shows your reading.
- Probes: this is what you want to plug in to measure. There are two probes red and black.
These are the outer basic structures of a multimeter which are commonly known to all.
How to measure a voltage:
Voltage measurements are the potential difference between the two points. Commonly, the voltage is measured between a particular point and the ground or zero line on a circuit. But it doesn’t mean that the voltage can be measured between any two points.
Voltage is one of the easiest measurements to make by using anyone like an analog or digital multimeter.
The main advantage of voltage measurements is, it can be made by probing directly onto the relevant points of the circuit. You can measure both DC or AC voltage.
*V -the straight line indicates DC voltage.
*V~ wavy lines indicated AC voltage.
- Turn on your multimeter
- If you’re measuring the AC voltage means, set the mode to v with a wavy line or if you’re measuring a DC voltage means, then set the mode to v with straight lines.
- Be sure that the red probe is connected to the dock with a V next to it.
- Connect the red probe to the positive side of the component, where the current is coming from.
- Then connect the black probe(COM probe) to the other side of your component.
- Finally, read and note the value shown on the display.
To measure voltage, you have to connect your multimeter parallel with a component in which you want to measure.
How to measure a current:
Current is one of the basic electrical/electronic parameters, so it is often necessary to measure the current flowing in the circuit to check its flow.
Current measurement can be measured in various way, but the multimeter is the most commonly used equipment to measure it.
Current measurements are very easy to make, but there are slight differences that occur way to way in which voltage and other measurements are done.
Before measuring the circuit, be sure that you are plugged the red probe in the right port.
- Turn on your multimeter.
- Insert the probes into correct connection.
- Set the main sector switch on the meter to the correct measurement type and range for the measurement to be made.
- Optimize the range for the best readings.
- Note the reading, then for precautions place the probes into the voltage measurement sockets.
How to measure resistance:
Measuring a resistance is one of the important measurements made by a multimeter. It can use the same principle in both analog and a digital multimeter to resistance measurements.
- Turn on your multimeter.
- Select the item for which the resistance to be measured.
- Insert the red probes in where the ohms sign is visible and black probe to another side.
- Select the required range. With this most accurate measurement can be made.
- Zero the meter, If the range is changed then repeat this process.
- Note the readings which display on the screens.
With this common steps, you also need to focus on your multimeter whether, it works without error or not.
Electric measurement device occurs errors easily. So be sure with checking your multimeter accuracy.
To get a perfect reading always choose a branded one. This multimeter is one of the basic devices like drills and Sanders that are to be kept in the home.
With these working steps, you can easily identify and measure the voltage, current, and resistance.