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What Does Negative Voltage Mean on a Multimeter

While measuring a circuit’s voltage, you may have noticed a negative voltage reading on your multimeter. So don’t be confused; we will explain to you the reason behind this negative voltage. A negative voltage is just an error or it’s applicable you might also say about this. In this article we will discuss what does negative voltage mean on a Multimeter.

The negative voltage is basically used in transistors, in the telecom industry, and also in amplifiers to control overheating electrochemical reactions. As you know, -48 V is used in the telecom industry.

This may be confusing for learners, but it’s necessary to understand this fault. If you want to keep working on a multimeter then you need to know first about its functions. It is a type of voltage that is less than zero. Another says it is a voltage that is pointing in the opposite direction of the positive (+).

A negative voltage is used in electrical systems to control the power flow.

Multimeter reading indicates that there is currently flowing in the opposite direction of positive.

A few reasons why your multimeter shows you negative voltage:

The Meter is set to reverse polarity.

This is a common problem with learners when they measure DC voltage. To fix this, you can just switch the lead at measuring points. The red cord will be connected with the positive measurement point and the black one with the negative dot.

A break in the circuit will cause a short circuit.

You will need to find the breakage in the circuit and repair the circuit breaker. Now you should first check the transformer and the diode.

You’re measuring the voltage that is negative relative to the ground.

If you are measuring the voltage between two points in a circuit with respect to ground, one point is at ground potential and another one is at volts.

Here’s the multimeter it’s set to measure DC voltage and there are two batteries. One of them is pretty strange so it’s a rechargeable battery, a triple – a nick metal hot rod.

Two wires connect with a multimeter, the red one is positive and the black one is negative. So let’s take measurement red goes the plus and the multimeter shows volts DC. Take the battery and put red wire on plus + and negative on minus –, the multimeter shows negative volts. Now let’s reverse, you can change the sides of wires and put black on the plus and red on the minus, it shows positive. It means when a multimeter shows negative voltage you need to reverse the direction of multimeter wires.

How to find Positive and Negative wires.

This is a very simple method, first, you need to get a glass of water then you need to immerse the two ends of wires of the power source inside this glass of water then you need to switch on your power source. After a few seconds, your negative pole will start creating bubbles. So from this method, you can easily identify the negative pole which is creating bubbles.

What Does Negative Voltage Mean on a Multimeter

Use Of Multimeter

We will tell you to properly use a multimeter and we will be covering how to measure DC voltage, AC voltage, resistance, continuity, and also how to measure amperes.

We will tell you how you can calculate the watts and amps for any device.

Let’s start with DC voltage. Basically, the DC voltage in devices we use each day are batteries so pretty much all devices that use a battery run on DC voltage,

For example, any device on your car runs off the car battery, your wireless drill, or any camera that runs on batteries that use DC voltage. DC voltage stands for Direct Current and when using the multimeter to measure DC. The voltage you need to set is here where you see V for voltage with these straight dotted lines. Next, you need to make sure your test leads are in the right location, your black ground or common test lead will always need to be here where it says COM. But your red test lead is the one that you’ll need to be around based on what you are measuring. And for measuring voltage you need to place your red test lead where the sign for voltage is. Next, you place your red test lead on the positive or powered side of the device or circuit you are measuring and the black test leads on the ground side.

And as far as where to exactly set the dial on your multimeter, you want to set the dial to the number just above the maximum amount of voltage you are measuring. So for this 1.5v AA battery, we can set it to 2 volts and as you can know we have volts. It means this is a fully charged battery because it shows 1.616 volts. But if you are unsure about how much voltage you are supposed to measure you can always start higher and come lower to get a more precise measurement. And we are going to measure the voltage on this 12-volt car battery but we also know a negative sign, basically, that just means we have our test leads on the circuit backward, this doesn’t hurt the multimeter but it is a good way to find out your positive and ground side when you ensure which one is which.

Next up AC voltage, basically, any device that plugs into your wall socket runs on AC voltage, AC voltage stands for Alternating Current and when measuring your AC voltage your red lead stays in the slot, but you need to set your dial where you have the voltage sign but also this wave sign. So if we want to see if we have current at a wall socket, for example, we set our multimeter to 200 in the AC voltage area, and that is because in the US we get about 110 volts at the socket.

Now a word of caution when measuring high voltage like this you need to be a hundred percent sure of the integrity of your multimeter and the test leads, plus when you take your measurements make sure you keep your fingers far from the tip of the test leads and that the leads don’t come close to each other at when you are taking the measurements. For added safety. you can always wear gloves too. So next we put in our test leads, first the ground which goes here where the bigger hole is, and then our red test lead on the other side which goes into the smaller hole which is the power side, and as you can know we have 118.7 volts which are good. Between the lower bottom, one is the wall unit ground point and a good way to see if it is grounded is to put your ground test lead on here and measure the voltage as well.

Ch Ashraf
With over 25 years of electrical contracting experience in the Gilawala area, Ashraf Electric provides reliable and efficient residential, commercial, and light industrial electrical services. As a locally owned company based in Lodhran, we specialize in quickly diagnosing and resolving electrical issues both big and small. Our team of highly skilled electricians is available 24/7 to ensure your electrical systems continue running safely. Whether you require a full rewiring, socket and switch upgrades, safety inspections, or lightning protection systems, contact Ashraf Electric for exceptional customer service and quality electrical workmanship.