Learn How to Use a Multimeter Using a multimeter correctly can save you from costly repairs and help you diagnose problems with electrical or electronic equipment.
Learn How to Use a Multimeter
Multimeters are small, relatively inexpensive, analog or digital hand-held devices used to measure a variety of electrical parameters such as current, voltage, resistance, temperature, continuity, and capacitance. A multimeter effectively “talks” to the device you’re testing, giving you immediate, accurate readings. Here’s a step-by-step guide to understand what and how to use a multimeter to take accurate readings.
What is a Multimeter?
A multimeter is a handheld electronic measuring device primarily used in electrical and electronic work. These simple-to-operate devices are suitable for a wide range of uses, from domestic repairs to industrial maintenance, and can help you diagnose problems with appliances, wiring, electronics, and beyond.
Multimeter devices fall into two basic categories: analog or digital. Analog meters feature a needle that moves to indicate the current measured value. Digital multimeters have a readout display, typically an LCD screen, displaying digital numbers. They are now preferred over analog for most all uses since digital versions are more accurate and easy to read.
Parts and Tools
To get you started, you will need a few different parts and tools. Here’s a rough list of what you’ll need:
Parts:
- Multimeter – digital or analog.
- Test lead set with two cables and probes.
- Alligator clip if necessary.
- Battery.
Tools:
- Screwdrivers.
- Voltage tester.
- Safety glasses or goggles.
- Heavy duty gloves.
How to Use a Multimeter?
Now that we’ve gone through the basics of multimeters, let’s run through the steps to using one and taking the readings. But first, you should know the following safety tips:
- Never touch both probe tips at the same time when testing an electrical or electronic circuit.
- Never use a multimeter to measure voltage greater than the rated voltage of the meter.
- Avoid touching any live circuits or metal parts while testing.
- Always wear safety glasses and insulated gloves while using the multimeter.
- Do not use a multimeter to measure current if you are not sure what type of protect the meter has.
Step 1 – Turning the Multimeter on and Setting It to the Appropriate Measurement
The first step is to set the mode selector knob to the desired range. This knob will usually be either a rotary dial, if you’re using an analog multimeter, or button, if you’re using a digital multimeter. Most multimeters will allow you to select whether to measure volts, current, or resistance.
Learn How to Use a Multimeter
Once you’ve set the range, it’s time to plug the black lead into the “common” jack on the meter (usually labeled COM) and the red lead into the desired jack. Digital multimeters may also have a jack labeled “peak” for the highest value it can measure.
Next, insert a battery into the battery compartments of the multimeter for power source, and turn the meter on.
Step 2 – Connect Leads and Take Readings
At this point, simply connect the leads you have connected to the multimeter to the device you want to measure. Typically, the black lead (or negative) will go in the negative outlet, and the red lead (or positive) will go in the positive outlet. For digital multimeters, ensure the display reads 0 before connecting it to the device in order for the meter to provide accurate readings.
Once you’ve made the connection, you’re ready to take readings. If you’re measuring voltage, make sure that the display reading is within the voltage range you set earlier. If it’s too high, you should turn the meter off and adjust the range accordingly.
Learn How to Use a Multimeter
For current readings, connect the leads to the current reading range on the meter and turn the current adjustment knob to the highest range. Once you’ve taken the reading, check to make sure it matches your expectation.
Finally, for resistance readings, connect the leads to the resistance/ohms range on the meter and rotate the range switch to the highest range. Activate the test pushbutton to measure the resistance on the device.
Step 3 – Interpreting the Readings and Disconnecting the Leads
Interpreting the readings from a multimeter can be tricky. On digital multimeters, the display will show a number followed by a decimal point. This indicates how many zeros you need to add to the number to get the complete value. For example, if the reading is 0.3V, then the complete value is actually 0.3V or 0.3 volts.
Learn How to Use a Multimeter
The meter can also display error codes to indicate an invalid measurement. Different codes may be displayed for over- or under-range readings, or for a technical issue. Consult your user manual to help determine what the issue is if you encounter any of these codes.
Once you’ve taken and analyzed the readings, disconnect the leads and turn off the multimeter.
FAQ
Q: What are the Different Types of Multimeters?
A: Multimeters fall into two categories: analog and digital. Analog meters display the readings as a needle moving from highest to lowest voltage. Digital multimeters are more accurate and display the readings as digital numbers.
Q: What’s the Difference Between Resistance and Current?
A: Resistance is measured in ohms, and current is measured in amperes (amps). Resistance measures how a material or device opposes the flow of electricity, whereas current measures the rate at which electrons are flowing through a material or device.
Q: What is the Safety Risks of Using A Multimeter?
A: Before using a multimeter, you should always wear safety glasses and insulated gloves. You should also never touch both probe tips at the same time when testing an electrical or electronic circuit, to avoid the risk of electric shock.
Q: How Does a Multimeter Work?
A: A multimeter is a hand-held electronic measuring device that can measure electrical parameters such as current, voltage, and resistance. It has components such as test lead set with two cables and probes, a rotary dial, or button (for digital multimeters), and a readout display (typically an LCD panel). When measuring the voltage, the multimeter measures the difference in electric potential between two points in an electric circuit.
Q: What Features Should I Look For When Buying a Multimeter?
A: When buying a multimeter, consider the ranges of measurements you need, the type of display (analog or digital), and whether it has specialized features such as temperature or frequency measurements, or data logging capabilities. Additionally, consider the cost, durability, and how easy the device is to use.
Q: How Can I Make Sure My Readings are Accurate?
A: Make sure the range of your multimeter is adjusted to the reading you need to take. Ensure that the display reads 0 prior to connecting the multimeter to a device for voltage readings. Additionally, check the reading against your expectations and consult your user manual to help interpret any error codes that may show up on the display.
Conclusion
Using a multimeter can be an excellent tool in diagnosing electrical and electronic faults. Multimeters are simple-to-operate devices that measure a wide range of parameters and can save you time and money. Always follow the safety precautions and use the correct settings when using a multimeter to get the best results.
Learn How to Use a Multimeter
To make sure you get the most accurate readings, it’s important to understand the basics of how a multimeter works, the components and tools you need, and the steps to correctly setting it up and taking readings. Practice using your multimeter regularly to ensure accuracy.
Now that you know the basics of using a multimeter, you’re ready to start measuring electrical signals!