Episode: 3534
Title: HPR3534: Vernier caliper
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr3534/hpr3534.mp3
Transcribed: 2025-10-25 01:04:17

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This is Haka Public Radio episode 3534 for first ever 17th of February 2022, today's show
is entitled Burnier Caliper, it is hosted by Ken Fallon and is about 1 minute long and
carries a clean flag. The summary is, Ken recommends my Reducesful dual formettering stuff.
Hi everybody, my name is Ken Fallon and you're listening to another episode of Haka Public Radio.
Today is a show that I wanted to do for some time but I was prompted to do it for two reasons, one
that were short of shows and I wanted to get this message out to you so if you haven't submitted
a show this year, please consider doing that immediately. If you have never submitted a show,
then please consider introducing yourself to the community. Okay, the reason I'm bringing this up
now, the other reason that I'm bringing this up now is that I was on a video call yesterday and
somebody noticed this in the background and I realized I had wanted to do a show about this for a
long time and it is the Burnier Calipers. What's a Burnier Calipers you asked? Well, it's actually a
tool used for measuring stuff that's along the short of it. I came across this for the first time
in my first year of engineering and if you don't have one, it's very, very useful thing to have.
Let me just describe it for you. It composes of two parts. The first part
is a piece of metal in the shape of a T. There's a long edge on the left hand side of the top
of the T with a chamfer to a point and there's a short edge on the right hand side with a chamfer
to a point or you could say on the bottom there's a long edge and then top there's a long edge.
Then inside of that sliding up and down the along base about 30 centimeters or a foot,
no actually it's 15 centimeters or a foot, a half a foot, then there is a slider and my one,
the slider has 0 to 9, 0 to 10 actually and 0 to 25 of 0.001 inches. So the top is imperial
and the bottom is metric. You can get various different ones, you can even get digital ones or
ones with a dial on them but I have like an ultimate cheapy. So what this thing does is it allows
you to measure various different dimensions of a component and I've seen people use the scrape
a bit for that when you get a dimension so you set it as accurately as one centimeter then you can
scrape off a line, a mark. I was always thrown upon that you shouldn't do that but it seems to be
a fairly standard thing and this thing I picked up for less than a tenor and you can get cheaper ones
made of plastic that actually work out that seem to be quite well good as well. So when you open
it out not only does the slider slide along the measurement you know but a metal pin sticks out
the bottom and the reason for that is you can get three different types of dimensions. So if we go
through the Wikipedia article which I recommend you reading we have the first part is the outside
jaws and these are used to measure external diameters of an object like for example the outside
of a cylinder or the width of an object like a rod or something like that or if you just wanted to
say well I want to have three centimeters there a market and then you can scrape your mark along.
Then we have the inside jaws where it goes inside the object itself and you can measure the
internal diameter so you would use the outside one to measure maybe the outside of a pipe
and you would use these inside ones to measure the inside of a pipe very very useful thing
and then the depth probe or rod is used to measure the depth of an object so if there was a pipe for
instance you would you could drop that inside the pipe rested on the top and the rod would go down
to the ground for example and you would be able to measure that there and mine has also a little
screw at the top that you can use for lucky I got I have a digital one that was more expensive
but it invariably runs out of batteries whenever I want to use it and this one I got real cheap
and it's up in the back it's got a sticker with the conversion from millimeters to widthwork
and various different types of thread but so basically if you just use it as a regular old bog
standard rule you know if you're doing woodwork or something like that it's just absolutely fine
if you're doing the tiniest little bit of metalwork or something you want to take a screw and
or a nail or something and find out well is what is the exact dimension there's a really
cool aspect of this that you can do and that is you can get accuracies to 0.1 of a millimeter
or the equivalent in in Imperial and how you do that is as you grasp something on the jaw so I'm
just going to pick up here and I got graphs on the outer jaws and I see a pencil it is a
big viral so I'm grasping that in the outer jaws and I see that the zero on the scale so it lines
up with the one two three so sorry it is five centimeters six centimeters seven centimeters so it's
more than seven centimeters but less than eight centimeters so we know it's seven points something
now and we can tell that because that's where the first zero on the sliding scale is
but the first the sliding scale doesn't line up with the scale on the vernier calipers itself
no it doesn't it's offset slightly so that as you look along that line and you see where the
markings line up with the numbers on the sliding scale you will see that you can get your second
point measurement so I've already said this is five six seven points something and I look along and
I see this the one on the sliding scale kind of is somewhere between the 12 and the 13 now that's
not what I'm looking for the two is getting very close to 15 670 the three is not quite over the
22 and the 22 doesn't matter all you're doing is you're looking to see where the bottom line
marks up with any of the centimeter lines and I see that five marks up with one of the centimeter
lines perfectly so I can say with relative degree of confidence that this is 7.5 is the dimension
outside dimension of this and it's knuckle that's close enough for jazz close enough for basically
close enough for jazz it's a really really useful tool to have you would be amazed at how often
you would use it for example I want quickly measure a piece of perspex over here I measure it
and I see that it is more or less four and even then having a sliding one with imperial
is quite useful as well because you can see if the thread that you're working on if it's not
really fitting nicely into a metric system which is used commonly over here then you can see
that oh this could be an imperial thread and there's a a standard imperial or a withword thread
that I can use so very very useful I highly recommend if you do anything around the housey but
you know it's a very useful thing to do I was the other day measuring up I needed a little plastic
for a window and it was just handy to be able to get in there with the inside jaws and in the gap
and measure how much of a gap is is there in real terms so that was my tip for near calipers
if you don't have them have a look see if you can get one you can get the plastic ones which are
I don't know if they call them plastic or they carbon fiber reinforce something but they seem
to be also under five dollars something like that I've seen I've seen a big clive do a breakdown
on them and they seemed to be reading off the scale so that a new positionally where it was
on the thing so that's it's tuned in tomorrow for another exciting episode of hacker public
radio you've been listening to hacker public radio at hackerpublicradio.org today's show was
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