Okay, now that you have known the various types of multimeters and have understood which ones are the best, it is time to understand how best to use your device. If you don’t know how to properly use a multimeter, you stand a great risk of electric shock or damage to your electronics. Moreover, you may end up blaming the multimeter for not functioning effectively, whereas the main problem was because of inadequate knowledge in usability. This segment will educate you on the proper use of the multimeter and how best to use it when measuring circuits. Before we talk about its various uses, let’s look at the different parts of the multimeter. A multimeter has three main parts: the ports, selection knob, and the display.
The display has the capacity to display a negative sign and it usually has four digits. Some multimeters even have illuminated displays for better viewing in the dark. The knob selection enables the user read different things such as the resistance, voltage, and current. There are four probes usually found in a multimeter but there are different types of probes used by different types of multimeters. There are banana to test probes (which are perfect when replacing broken probes), banana to tweezers, banana to IC hook, and banana clips. The last on the list are very important for connecting to pins or large wires on a breadboard. They are great for conducting longer test where it is not necessary to keep the probes in place while manipulating a circuit.
Measuring Voltage with the multimeter
To measure voltage on most electrical units (such as the AA battery), plug the red probe into the mAVΩ and the black probe into the COM. The multimeter should be set in the direct current range at 2V. Remember that most portable electronics do not make use of alternating current but rather direct current. So, connect the red probe to the `+` or to the power and the black probe to the `-` or the battery`s ground. Apart from testing the whole circuit, it is also possible to test different parts of the circuit. This is known as nodal analysis.
When measuring a DC voltage (such as a sensor or a battery), you need to place the knob where the V has a straight line. If you are still learning how to use the multimeter, it is not advisable to use the AC voltage setting because it can be really dangerous. But if you are performing a task that requires you to use the AC voltage testing, it will be more ideal to make use of a non-contest tester instead of a multimeter. The reading on the meter becomes negative if you switch the black and red probes.
How to deal with overload when measuring
Sometimes you may choose a voltage setting that is lower than what you want to measure, In this case, a proper functioning multimeter will indicate to you and alert you that the voltage is out of range or overloaded (usually indicated by a simple display of 1). To resolve this issue, change the multimeter knob and bring it down to the next highest setting. This will definitely keep things normal and help you effectively perform your measurements.
Using the multimeter to measure Resistance
With the advent of the internet, most resistors can be easily measured through the help of online calculations. But if you don’t have access to the internet, don’t worry because the multimeter is also a handy tool when measuring resistance. And measuring resistance with the multimeter is also easy. Just select your resistor and place the meter to the 20kΩ setting. Afterwards, hold the probes to the base of the resistor legs with a slight pressure. The multimeter will now read 0.97, 1, or 0.00. The first is the actual resistor value or about 1000Ω. If the multimeter displays OL or 1, it means it is overloaded. You can then place it on a higher mode such as 2MΩ or 200 kΩ. This does not really cause any harm, you just have to adjust the knob and place it at the proper range.
But if the meter is reading 0.00 or close to zero, it means that you need to reduce the mode to 200Ω or 2kΩ. It’s not always ideal to measure resistance when the device is still installed in a circuit. The components on the circuit board may seriously alter the reading. Moreover, temperature can also effect the reading to a great extent. So, measuring resistance cannot be always perfect unlike other units like measuring current or voltage.
Measuring current is one of the most common uses of the multimeter. In fact, all multimeters (whether basic or advanced) have the capacity to measure current. But despite its popularity, measuring current is one of the most insightful and trickiest measurement readings in the world of electrical measurement. What makes it tricky is because you have to measure them in series and not as a whole. Measuring current is the only procedure you have to physically stop the flow of current and place the meter in the line of the current.
When measuring current, you’ll need a piece of wire which you’ll use to physically interrupt the flow of current to the circuit you intend to measure. Connect the wire from the probe to the resistor and then place the multimeter in-line with the current flow so that it measures the current as it flows into the bread board through the multimeter.
Once the multimeter is connected, you can then place the correct dial using the right setting to measure some current. Just like measuring resistance and voltage, you need to get the right range when measuring current. Begin with a 200mA and go on from there if that’s not enough. But if you feel the circuit may make use of more than 200mA, you can adjust to a higher probe, just to be safe. When measuring resistance or voltage, an overload may only result to a wrong display and no serious damage. But an overloaded current can result to a blown fuse, which may cost you a lot of dollars for replacement. So, you have to be very careful here when measuring current.
How to Use a Multimeter Video Tutorial
The above are the basic measuring capabilities of the multimeter. There are other uses of this device such as measuring amerage and continuity. The measurements are all performed in similar fashions as current, voltage, or resistance measurements. As you begin, with time you will get quite used to the different uses and protect yourself better.