Measuring voltage voltage type there is two types of voltage which is DC and AC and we did mention the
difference between them earlier when measuring voltage at the meter blobs are placed across the voltage
source the Volt or meter are used to separate functions and ranges to measure DC and AC because AC is
constantly changing with form measuring AC voltage is not a simple matter.
This Volt on meet our emissions base with automatic voltage and we must mention that when measuring
voltage the Volt on meter is used to by the voltage across the source which is different than when measuring
current with the current in the circuit must flow through the Volt or meter to be measured.
This make it far easier to measure voltage and circuit because the operator can simply place the probes
across the component as it is while in the circuit while measuring current that both brutal the operator
must physically interrupt the circuit unsold of and connect and insert the Volt o meter into the circuit.
So you might have to unseal that component of that its connection so that you can measure the current
flowing through it burnt.
We must point out that the two voltage measurement ranges one for DC and other for the C and we will
see how to measure both of these.
Now let's look at this digital multimeter or Volt or meter.
Uh we must skin set to host predictable.
If we are measuring resistance and we doesn't know or we don't know how much that resistance is we must.
But the scale of the highest value.
Now we the props must be inserted into the sharks as you can see here and we must know the voltage polarity.
As you can see in these two batteries this side is the positive.
And this battery this side is the positive.
So we must bless the positive Rob here and the negative probe here to better measure the voltage.
Now let's look at how we can measure that battery voltage.
Set up the Volt or meter on six hundred volt DC.
As you can see here we are pointing at six hundred volt DC since this is a DC battery.
Uh we much or almost touch red blob two plus as in here as you can see this is the red blob.
And touch a black blob too negative as you can see here then we must read the voltage to the nearest
1 volt.
As you can see here this is a nine volt battery so it's displaying nine.
And uh you can try this at home.
I'm sure that you have wanted me to run the battery.
Uh this is a very simple technique and we must be sure of what we choose.
Uh I'm measuring a DC current here so I choose volt DC for measuring ac I must choose volt AC so you
must take very good care of this setup before I start measuring anything.
And now let's touch the blob.
The negative battery that the blob as you can see here we are reversing the connection and we touch
the black blob to the positive side.
We are reversing the connection.
Uh and we read the voltage to the nearest 1 volt.
As you can see there is a minus sign here which shows the world is negative.
Since we are measuring it in the reverse manner the purpose of this exercise is to show that the Volt
o meter can tell the difference between negative and positive voltages.
We must point out that some Volt or meter particular another type will not be as forgiving that putting
the probes on reverse voltage can damage the meter.
So if you have an analog Volt or meter you shouldn't try this uh just place the positive on the positive
side on the negative on the negative side.
Now let's see if we are to out another to take another example using a vulgar scale that is closer to
the actual voltage shown an improvement in the resolution.
So if we know that this is an eye involved better while choosing a 600 volt scale or if we are or we
know that this battery will measure a Volt between 1 and 20 why choosing 600.
This will decrease the resolution significantly.
Uh in this case we know that this is a 9 volt battery so we are adjusting the scale now set up the rule
involved o meter on 200 volt DC skid touch red blob.
The positive and touch black properties are the negative.
Let's read the voltage to the nearest point to unfold.
Not one volt as you can see in nine point five volt.
Which means that we have a way a much higher resolution.
Uh this is very silly.
There is a zero here.
Now we if we did another adjustment and blazed the Volt o meter and the 200 volt DC scale as you can
see here.
Now let's touch the red blob to the positive and the black blob that are negative and read the voltage
the nearest Born 0 1 volt as you can see here nine point five and the zero claim here unlike the previous
example.
As you can see the Zero was here.
Now it's here.
So we have our much higher resolution.
This is a very good example uh that you must at least have a clue how much the voltage should be or
in what range so that you can get a good result.
Now let's start let's look at this one point five volt battery example.
Set up the Volt or meet up to 20 volt DC touch.
The red blob and the black robe and the positive and negative direction using our unborn 5 volt battery.
Read the voltage thumbnails buoyant 01 volt.
As you can see it's a three.
Breathing is one point five two.
The tool here means that we have a very very high resolution and that we can measure in military volt
range not just the Volt range.
Now let's see the next example in which we will look at the battery but in the middle of volt scale.
Now let's set the Volt on Meet of the 2 200 million volts skin the scale reading two hundred two thousand
Miller Volt or two volts.
Does that add up to the positive and the black blob.
There we go.
OK.
Now we are using the 2000 scare.
Well actually using the two volt scared because two thousand million volts is the same as two volts
but because that simply is in level.
That is not the small point in this case a rating of one thousand five hundred twenty seven million
volt is the same as one point five to seven Volt.
So as you can see here we are using them in the Volt range and we are sitting here and Volt o meter
as you can see now.
And this one point five volt battery we carry the voltage Tony Harris volt 0 0 1 volt and the rating
is given as 1500 to 27 volt it's equal to one point five to seven Volt.
So as the same.
But you just make the resolution however much higher.
Now to see if we want to look at the other example in this example we are setting our volt meter on
2000 level this is scale and we are touching the red blob with the positive and the negative Rob with
the negative side.
We are using a nine volt battery and this is clearly an over voltage situation not reading it Swan.
So you must know what happens if you use a scale that is too low for the voltage being major.
As long as you do not exceed the maximum voltage value of the meter in this case six hundred volt there
will be no physical damage to the meter.
Let me tell indicates an over voltage situation by displaying a single digit one of the far left.
This over a overage indication is consistent with the over all the other functions to be looked at later.
So one means that we have over voltage and we didn't choose the right resolution.
Now let's talk about safety and measuring uh when measuring voltage the voltage being measured execs
is exposed to the operator and flowing through the props by cautions B alternative or be attentive.
Watch what you watch what you touch.
We shouldn't touch the props while measuring voltage.
The blobs have sharp buoyant so that you can make precious contact.
Use the protective shields when probes not in use so that they won't harm anyone.
Observe the meter maximum limits for voltage and current fuels are a last resort protection feature.
If you blow a fuse you made a mistake a very big one actually.
So you must spend some time in safety so that you won't get harm or you won't harm anyone around you.
The operators of the Volt meter could be exposed to lethal voltage and current levels also in probing
alive circuit careless cross contact and the resulting short circuits could draw out equipment damaging
levels of voltage and current the circuit under test.
So you might harm the circuit damage components while measuring all while using digital multimeter or
Volt or meter uh you must practice before going to circuits.
You must practice with the components you must practice with damaged circuits then go to the real life
circuits and real life problems.
A good technique is the do a dry run of broad placement with mouth turned off during the dry run.
The operator can see if the probe placement is correct and not short circuiting to damaging voltage
and current breaths.
Probably Osment and once confidence turn on the ball source to make the measurement another good technique
is to sort all measurement of the high scaling level and then adjust the scale down downward to the
appropriate living.
There are usually automatic protection features involved or meters but it is the best or it is best
not to consistently depend on them doing their intended jobs.
That's it for measuring voltage and for safety and measuring voltage.
I know that this lesson was really long but I'm sure that you learned a lot of things in one lecture
and we kept it connected since this all experience are related to each other.
Thanks for watching.
See you next in measuring color.