This is a universal bevel protractor Often referred to as a vernier protractor and its purpose is to measure angles There are several different parts to this Universal bevel protractor What we have here is the base That the measurement is taken from it also acts as an area for an acute angle Attachment tool to be added to which I'll show you in another photo Down here, we have the blade which is actually inserted through a groove and tightened with this knot here and It actually will articulate around the protractor and Allow you to measure the angle against the base We have two scales on this protractor, we have a main scale and there's actually four quadrants of it of 90 degrees So if you have a look here, you can see 90 degrees and then it goes right And it goes left of that 90 degrees If you have a look just underneath this magnifying glass here, which is used to help Magnify the measurement because it can be a little tough to read. We actually have the vernier scale this scale is divided into two quadrants of 12 divisions each and What is trying to do is is trying to magnify the degree. So in other words, it'll break a degree down into twelve parts or Five minutes of a degree. So the accuracy of this tool is five minutes of one degree We have a lock nut here. So if we unlock this nut we can then swivel the blade Swiveling the main scale to whatever angle we require and then we can tighten it This is a fine adjusting wheel So once the lock nut is unlocked we can use this to turn to dial the angle into whatever degree we require This photo shows the universal bevel protractor checking a part The part would be set in against the base and with the lock nut loosened this blade would then be brought? Into contact with the far side of the part and then the reading is taken off of the scale here This is an example of the angle being checked on another part This picture shows the acute angle attachment which has been added to the base of the universal bevel protractor This is used to measure angles smaller than 90 degrees Let's have a look at how the universal bevel protractor is read So if you have a look on the main scale here you can see Each division is a full degree This particular one happens to be going in the counterclockwise direction If you have a look down on the vernier scale you will notice there are two sides to it There is a scale from 0 to 60 going in the counterclockwise direction And we also have a scale from 0 to 60 that goes in the clockwise direction. This will become very important so we want to have a look at the zero on the vernier scale and line it up with the main scale and You can see we're just slightly past 40 41 42 43 44 45 degrees not quite 46 degrees so we can say that the main scale has an accuracy of 45 degrees now After we find out the full degrees We're going to put our eyes down onto the vernier scale and we're going to start to move along it again Because the main scale moved in the counterclockwise direction we're going to do the same thing on the vernier scale This is really important So again each graduation on the vernier scale is five minutes of a degree So we're going to have a look down until we see a line that lines up with the main scale So 5 minutes 10 minutes 15 minutes 20 minutes 25 minutes 30 35 40 and it looks to me like the 45 minute symbol lines up, so we can say that the accuracy of this particular reading is 45 to Riis 45 minutes Here's an example of another reading please notice how the scale this time is going in the clockwise direction So if we have a look at the vernier scale, you will notice it's past the 10 degrees as a matter of fact It's 11 12 13 14 but not quite to the 15 degree so we can say that the main scale has a reading of 14 degrees Now we're going to take our eyes down onto the vernier scale. And what direction are we going to read in? That's right, because we read the main scale in the clockwise direction We're now going to read the vernier scale in the clockwise direction So we have a look down here and we're going to look for a line that lines up with the main scale So 5 minutes 10 minutes 15 minutes 20 minutes 25 minutes and it looks like the 30 minutes is where it lines up so we could say this reading is 14 degrees and 30 minutes, which is also 14 and a half degrees Let's try one last reading Again, you'll notice that the scale is moving in the clockwise direction The zero on the vernier scale is Just past 25 26 degrees not quite 27 degrees so we can say that the main scale has a reading of 26 degrees we'll take our eyes down and we'll look on the vernier scale and it looks like The 50 degree lines up so we can say this reading is 26 degrees 50 minutes What if we made an error and we had a look on the other side So if we were to go 26 degrees and then take a rise down to this side you'll notice That approximately to the 10 minutes lines up So if we were to say 26 degrees in 10 minutes You can see that would be quite an error from the true reading So again, if we are going if it's getting larger in the clockwise direction we want to make sure and Continue along in the clockwise direction on the vernier scale Just to recap this Universal bevel protractor Has four quadrants and each quadrant is 90 degrees and it runs in two directions either clockwise or counterclockwise Also - if we come down to the vernier scale You will notice it has broke up into twelve graduations each graduation being five minutes of a degree so we can say that the universal bevel protractor has an accuracy of five minutes of a degree