Today World News Online

Importance of Survival Skills

# MICROMETER SCREW GAUGE [Continuation]

hello guys welcome to Learning with Layi
this is the continuation video on how to take readings from vernier callipers and
micrometer screw gauge the micrometer screw gauge is quite different in
structure than the vernier calipers and it is used for measuring the diameter of
a piece of wire thin rods and object of similar small distances so let me show us
an image of micrometer screw gauge in case we might have forgotten and here with me now
from the previous video which I showed us before we have the micro screw meter
gauge with some parts labelled where we have the frame the anvil the spindle the
lock the thimble the ratchet knob sleeve and this part here now is the digitized
image of micro screw meter gauge whereby this main scale is actually what is
zoomed for us here to see and we have rotating scale we have the Thimble and
the object is actually placed in in between the spindle and the anvil and we can use
that to measure the distance of or the diameter of the thin rod or the object that
is placed there so now it is used and what we should know is that what we
should know is that there is always a pitch of 0.5 millimeters in the screw of
the thimble which now yields that 50 circular division is actually equal to 0.5 millimeters and
one circular division is actually equal to 0.1 millimeters so we have 50
circular division is actually equal to 0.5
millimeters and one circular division is actually 0.01 millimeter and I’m
actually going to explain this better so now and also in that same pitch where I
mentioned that it is of 0.5 millimeters the pitch that is in the screw which is 0.5
millimeters it means that for one for one revolution of the screw the
spindle moves forward or back 0.5 millimeters now let me take us back to that image so now in this part here now inside this thimble here there is a
pitch inside which is of 0.5 millimeter so when we turn our micro screw meter
gauge it moves forward or backward and that is occuring at one revolution and
since it is moving forward and backward it is going a distance or covering a
distance of 0.5 millimeters so now that’s the main idea that we need to know so
what we actually need to take notice that since we have our main scale here we
division that we have we will convert it almost like a similar case of the vernier
scale whereby we convert the vernier division to either centimeters or
millimeters depending on the manufacturer’s unit degraded on
the vernier scale so now in this case here now in it if you want to know the actual distace of this object here we are going to what we’re going to do is
that we’re going to take…. let me do it here on this page the distance of the
object d will be actually be equal to main scale reading plus rotating scale reading so
now I can also write it out on this micrometer screw gauge I’m not
actually going to repeat it so now the distance of the object let me write it
distance of object is actually going to be equal to the main scale reading plus
the rotating scale sometimes it is also called the drum circular…. from the
rotating scale rather is always having 50 circular division on the micros
micrometer screw gauge it has 50 circular division so for us to now
actually know the millimeters of the actual division the circular division
that coincides with the main scale because what we’re actually trying to look at is
the circular division that coincides with the main scale so then we now convert it to
millimeters and in most cases the unit on the main scale is always in
millimeters and while that of the circular division on the rotating scale reading
is actually equal to is also in millimeter so now let me now take us
to some examples that I’m going to solve and they’ll be a class work which you
can try to test your knowledge or understanding of it so here now I have
some readings of the micrometer screw gauge with me and we’re going to
actually write down the readings because this….
we can assume that the micrometer has been turned and this is the final
position whereby the the spindle and the anvil are actually holding onto the object
and we actually have a lock here in case if we remove the object so that the anvil and
the spindle doesn’t and shift from the initial position so now we have our
readings noted now so all what we are going to try and figure out is at what
point this is our main scale let me let me point it out so this is our main scale and this is the rotating scale here
in most cases they are always in millimeters in most cases they are
always in millimeter especially the rotating scale it is always in
millimeters now the main scale might depend on the manufacturer’s choice
whereby I can choose to put any other metric unit maybe centimeters but in most cases
the rotating scale is always in millimeters in most of text books I
checked before making this video so now how do we take down our reading now now
the formula to get the distance of the object we I tagged D is actually and
again sorry for that I omitted something so now our rotating scale reading is
going to be okay we would actually solve it here so now our main scale reading is
actually at what point we look at this now this is actually main scale because
the distance of the object which I’ve already written that I can write this as main
scale m dot s plus RS so and our main reading now is
that’s what eight point five millimeters now how do you now get the rotating
scale and the rotating scale is always in circular division
just like our vernier scale….. we count it in Vernier division then we use
that standard conversion that one vernier division is actually equal to 9 over
ten millimeters and in centimeters that will be 9 over hundred but in this case here now
we have our rotating scale and since we already figured out that for one circular
division that is going to be equal to 0.01 more millimeters therefore for and
if we look at it now the point of our coincidence with the main scale and our
circular division is actually going to be 27 because this is 25 this is 26 27 28 29 30
so this is the point here that means for 20 circular division that will now be 27 27
rather times 0.01 we have millimeters here now so that will now be actually so from here
now we will simplify this further this would be eight point five plus zero point two seven since they are both
having the same unit I don’t need to repeat that will now be eight point
seven seven millimeters this is quite straightforward than the vernier scale now
let me do B so now to solve for B now if we look at it now
this is starting from zero that’s why i closed this part here now so now we can see it now
that the main scale reading is actually our distance…is what is our main scale reading
so that actually two millimeters so I have the unit of all these main scale and
the rotating scale and the rotating in scale in most cases always in millimeters and for the vernier
scale and the main scale Main scale is mostly not… that’s manufacturer’s
choice could be either Main scale is always in centimeters
whereas the vernier scale is always in millimeters but for the micro screw for
the micrometer screw gauge the main scale is actually in
millimeters while the in some cases depending on the manufacturers choice
but rotating scale in most cases always in millimeters so now we have this also
millimeters have this also in millimeter so now to calculate the readings from
this micro meter screw gauge so we have a mainscale reading to be two millimeters
plus our rotating scale let me change that our rotating scale is actually that plus so now what point does our rotating scale coincide
with the main scale and if you look at this that’s at nine nine circular division so
this would be nine times 0.01 millimeters so now when we solve this
this would now actually be two millimeters plus zero point zero nine millimeters so
now our final answer is now going to be two point zero nine so now we can try
and solve this other ones to check our understanding about how to take readings
from a micro screw micrometer sorry micrometer screw gauge then I’m going to
write out the answers for this other ones here and the answer for this one
let me use that in another pen the answer for c is actually 10.15 millimeter and for d
the answer is actually twelve point three five so there you have it guys if you
have any other suggestion or comment please kindly drop them below
and if you love this video and you found it educative please click the like button
and subscribe thank you