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Today’s cars and machines are composed of electrical equipment that need regular maintenance to make sure nothing would go wrong. One of the usual ways of troubleshooting all the car’s circuits is by using the best digital multimeters.
A digital multimeter is a device for measuring the voltage, current, resistance, and electrical continuity of circuit components. Through this tool, you can calculate and view the ohms, volts, and amps present in the circuits.
Other functions a multimeter serves are capacitance measurement, diode test, temperature, frequency, and transistor current gain.
Important Parts of the Multimeter
Working with a digital multimeter means knowing all of its parts. Handling a multimeter requires familiarity since it’s no ordinary measuring device. Here are the basic parts of your digital multimeter:
1. Dial: This is the arc-shaped scale seen through a window where you can identify the ranges of the circuits and the readings of your tests.
2. Selector switch or knob: This is the function button which allows you to switch to volts, amps, ohms, and even the scale of the meter.
3. Lead openings: These are two sockets, COM or Common, and V or O, standing for Volts or Ohms respectively.
4. Test leads: These are black and red test leads used to connect to the device you are measuring.
5. Battery and fuse compartment: Found at the back of the device, this is where your power source comes from when you conduct testing.
6. Zero adjustment knob: This is a small knob beside the dial that is only for adjusting the resistance or Ohms range.
Testing Open Circuits
An open circuit is the simplest and easiest to troubleshoot. It just involves isolating the circuit from the power and the ground, and then connect the self-powered test light to the ground side of the circuit.
Afterwards, you can start probing and then observe whether the light is out throughout the whole period, or if it is switched on. If it remains off, then the open is situated in the middle of the circuit and the probe.
On the other hand, if it is on, then the open is in between the probe and the end of the circuit.
Testing Short Circuits
To prepare for short circuits, you must first isolate the circuit from the electricity source and the ground. Next, you need to connect the self-powered test light to a safe ground and then check any easy-to-reach point in the circuit.
Once you see a light turn on, it signals that there is a short somewhere in the circuit. To set apart the short, probe another test point at the furthermost part of the circuit. Keep in mind that the light should still be on and that’s when you can continue opening switches or removing parts.
Once the light goes out, it means that the short is now located between the last two circuit parts that were turned on.
Checking Working Diodes
After familiarizing yourself with the short and open circuits, you can now determine if your diodes, one-way current valve, are working properly. First, disconnect the diodes from any power source or tool with voltage because this will affect the meter’s reading.
Then connect a probe to the device you want to assess and refer to the meter. After this, use the other probe and take note of the second reading. If one of the readings are within the range of the dial, then it means that the diode is working.
On the other hand, if the first and second readings are out of range, then it signals a flaw or problem within your device.
To measure the voltage, you should first turn off the power source of the circuits or the wiring which have different voltages. With your multimeter are two probe leads colored black and red, which will be inserted in the COM socket and the V-labelled socket respectively.
Afterwards, turn the dial of the meter range to 20 volts because this will give you the most number of decimal places in the display. Then, you can connect your multimeter in parallel to a circuit to calculate the voltage.
Now you can touch your black probe lead at the first point of the wiring and right after, turn on the power source. Following this, touch your red probe at a second point of test with an adequate distance from the black touch point. Consequently, your multimeter will display the voltage reading.
Similar to voltage measurement, you have to turn off the power of the circuit being measured and your two probe leads will be connected into different sockets. The black probe will be plugged into the COM socket and the red one will be attached to the mA socket.
Next, you connect the multimeter to this series and set the dial to the range of 10 volts. Following this, you turn on the power once again and wait for the display to show the current measurement.
The 5 Best Digital Multimeters for the Money
1. INNOVA 3320 Auto-Ranging Digital Multimeter
What We Like
- Auto-ranging scales
- Drop protection
- Large display
For less than $20, you get to take home one of the most trusted brands in general electronics and automotive systems. This product from Innova is a handy and color-coded LED display multimeter with UL certification for safe and efficient electrical testing procedures.
It has a 3.5 inch LCD display, making it easier to read the scales and results. For hassle-free storage, Innova’s multimeter has attachable probe leads, holders for hands-free convenience, and rubber corner guards for protection.
Additionally, the instrument is lightweight, weighing 180 grams, with the 2 batteries included. Another feature that can prolong its lifespan is its automatic power shut down once the device is idle for 15 minutes. Because of its features, Innova’s nifty multimeter will be easy to carry around anytime, anywhere.
2. ELIKE T-92 Self-Recovery Digital Multimeter Amp/Ohm/Volt with Diode, Continuity, Capacitance, hFE, IR Detector and Livewire Identification
What We Like
- Audible continuity function
- Overload protection
- Infrared detector
ELIKE’s multimeter measures both AC and DC currents and their voltage, resistance, and capacitance. It boasts its audible continuity function that rings an alert if the circuit is able to conduct electricity.
Likewise, it shows the users when a battery replacement is already needed. This multimeter is also quick and efficient in delivering results as it produces 2 to 3 findings within seconds.
Another feature is the Infrared data detection, which helps monitoring the IR transmitters. For convenience, it has a built-in support stand and automatic power off feature for its users. Also included in the package is an outer case to protect the device.
3. Etekcity MSR-R500 Digital Multimeter, Volt Amp Ohm Meter with Diode and Continuity Test
What We Like
- Large backlit display
- Rubber sleeve for protection
- Built in support stand
This Etekcity product is able to measure current, voltage, resistance, transistor, continuity, and diode testing. Compared to similar products in the market, this is highly commended because of its wide functionality, reading accuracy, and premium on safety.
Its sampling frequency is up to 2 to 3 readings per second. Built for ease of use, this multimeter has a built-in support stand and a LCD backlight for trouble-free reading in dark-lit areas. Other impressive features of this product are the low-battery indicator on display, continuity buzzer, and overload protection.
You may consider this product as value for money since it includes a rubber sleeve protection for the device and a 1-year warranty for the customer. Just in case you need assistance in handling the product or free repair services, you can simply call on Etekcity and have the issue resolved instantly.
4. Neiko General Purpose AC/DC Hand-held Digital Multimeter with Diode Transistor Test Function
What We Like
- Ideal for car use
- Easy to read display
- Great for beginners
Built for straightforward functionality, this multimeter from Neiko is used to test car batteries, wirings, fuses, and circuits. You can use this for automobile or household electrical systems or equipment and find it very accurate in delivering measurements and results.
This product is compatible for reading your current, voltage, and resistance measurements and they will be viewed in an easy-to-read LCD screen. One of the best entry-level multimeters, Neiko’s product has other features such as diode testing and transistor testing. It’s no doubt that this product will give you a hassle-free time in the set up and handling during usage.
5. HDE® Digital Multimeter AC DC Power Tester
What We Like
- Very cheap
- Easy to use
HDE’s multimeter is the most basic, yet efficient model in its category. Despite having a single testing cable, it is capable of providing the necessary troubleshooting procedures for electrical equipment such as voltage, DC current, resistance measurements, and diode testing.
For less than $6, you can purchase a trademark HDE digital product that can assist you in tracing and solving car problems. This model is easy to carry around since it is pocket-sized. Though a small and light tool, this multimeter is an enormous help to your car’s electrical needs.
With the sea of choices offered to customers day in and day out, buying the essentials can be a difficult task. Digital multimeters are one of the car diagnostic necessities that every driver or owner must have within their reach.
With that said, you don’t have to buy the most expensive products nor the latest, most high-tech models available. As long as your multimeter has multiple features, durable components, and easy handling procedures, you’re well-equipped to start testing and fixing your wiring problems.