Thread: Vernier, dial and digital calipers

I've started to write a "paper" on the advantages and disadvantages of each type. When I'm finished (within the next few days) I'll put it in this forum (Metrology) and let's see if we agree or disagree on the advantages and disadvantages for each type. I will not put any caliper I'm even vaguely associated with in the paper It can, and will, be updated with all relevant facts from member's input including when no battery is required

I have a question re dial calipers. With metric dial calipers the scale is either one revolution per 0.5mm or 1mm. I personally find the 1mm per revolution easier to use to avoid a 0.5mm error but the 0.5mm does have the advantage of it being easier to read/see the value shown. That's one of the things I mean by advantages and disadvantages. Does the inch dial caliper come in more that one version and if so what are the versions? I don't think I've ever used a dial caliper that had inches simply because I live in a metric world so I have to ask.

Gordon

Originally Posted by Gordon B. Clarke

I've started to write a "paper" on the advantages and disadvantages of each type. When I'm finished (within the next few days) I'll put it in this forum (Metrology) and let's see if we agree or disagree on the advantages and disadvantages for each type. I will not put any caliper I'm even vaguely associated with in the paper It can, and will, be updated with all relevant facts from member's input including when no battery is required

I have a question re dial calipers. With metric dial calipers the scale is either one revolution per 0.5mm or 1mm. I personally find the 1mm per revolution easier to use to avoid a 0.5mm error but the 0.5mm does have the advantage of it being easier to read/see the value shown. That's one of the things I mean by advantages and disadvantages. Does the inch dial caliper come in more that one version and if so what are the versions? I don't think I've ever used a dial caliper that had inches simply because I live in a metric world so I have to ask.

Gordon

Don't know what I was thinking, or maybe I wasn't.

On metric dial calipers one revolution is either 1mm or 2mm, not as I wrote 0.5mm and 1mm. The question still remains - does the inch dial caliper come in two versions and if so, what are they?

Sorry.

I have only used one rev per .1". However, my knowledge is limited to my own tools. I can't wait to read your paper. Thanks for the effort!

Originally Posted by Gordon B. Clarke

does the inch dial caliper come in two versions and if so, what are they?

The vast majority of the ones I've encountered read 0.1" per revolution.

There are some real cheapos that read 0.25" per rev.

There are also dial calipers graduated in fractions rather than decimals.

- Leigh

Some of the mitutoyo dials read .200 per rev, and there are dials that read both inch and metric with two hands and scales.

Thanks for the replies but OMG came into my head. 0.1", 0.2", 0.25", fractions and both inches and mm are all options on a dial caliper.

I can't think of a better reason for going metric LOL

Gordon

P.S. I expect to have my "paper" finished by tomorrow (Sunday) and then let the comments and advice begin. It'll be as the usual PDF file as it's much easier for me to update and anyone clicking on the link will always see the latest version. Assuming of course I didn't get it right first time. Now that'd be a first

Please read this before opening the PDF file.

I've tried to be as impartial as possible and do not claim one type is better than another. They all have their unique advantages and disadvantages.

The pictures I've used are probably what most regard as being typical of each type.

What I hope will happen is that PM members correct me if I've written anything that they know to be wrong, or can be expressed better, and also suggest additions to the pros and cons. If it's from experience from practical use then this is by far preferable (to me) that any theoretical discussion.

The PDF file isn't information on how a caliper can and should be used as this information can be found in countless internet links. It is quite simply the pros and cons of the three caliper types.

One advantage can outweigh several disadvantages just as one disadvantage can nullify several advantages.

http://www.f-m-s.dk/Calipers%203%20types.pdf

Gordon

Originally Posted by Gordon B. Clarke

If it's from experience from practical use then this is by far preferable (to me) that any theoretical discussion.

Gordon

Calipers can also measure steps using the opposite end from the depth measurement shown in the first image. I've heard it said this is the most accurate part of the caliper but that for sure depends on the specifics of the situation.

Originally Posted by strokersix

Calipers can also measure steps using the opposite end from the depth measurement shown in the first image. I've heard it said this is the most accurate part of the caliper but that for sure depends on the specifics of the situation.

You're right but I did mention that in the first sentence after the bit on digital calipers. It does give a more stable reading when measuring from a longish flat to another than the depth rod but the "extra" inaccuracy I'm afraid is still the same as for internal and depth.

The best way to check the accuracy of the internal jaws BTW is to measure a small hole i.e. around 1/4" or 5mm. This shows how accurately the measuring "edges" have been ground.

Gordon

I think being able to set zero anywhere on the scale (and get both negative and positive values) is a specific feature of digital calipers you might want to add as an advantage.

What about what we used to call Master Verniers? (Not sure if that's the correct name.) These were the verniers with the separate thumb wheel for adjusting to size, similar to a height gauge. I found I had much better adjustment for feel with these, particularly on large inner diameters (24+ inhches).

Originally Posted by Sean the Dog

What about what we used to call Master Verniers? (Not sure if that's the correct name.) These were the verniers with the separate thumb wheel for adjusting to size, similar to a height gauge. I found I had much better adjustment for feel with these, particularly on large inner diameters (24+ inhches).

There are scores of special calipers. Both standard dial and digital calipers can have thumb wheels but I can't remember ever seeing a vernier caliper that had one. Do you mean the large calipers that go by the name "workshop calipers"?

In this thread and PDF file I'm only trying to deal with the three types of readouts regardless of size/length.

Originally Posted by SPDTool

I think being able to set zero anywhere on the scale (and get both negative and positive values) is a specific feature of digital calipers you might want to add as an advantage.

Thanks. It has now been added on and the PDF file updated

Gordon

Originally Posted by SPDTool

I think being able to set zero anywhere on the scale (and get both negative and positive values) is a specific feature of digital calipers...

You can do this with dial calipers also. Of course there's more mental gymnastics required than with digital.

- Leigh

Originally Posted by Sean the Dog

These were the verniers with the separate thumb wheel for adjusting to size, similar to a height gauge.

Here's a photo of an 18" Mitutoyo with that feature.


- Leigh

Originally Posted by The real Leigh

You can do this with dial calipers also. Of course there's more mental gymnastics required than with digital.

- Leigh

C'mon are you really wanting me to get a severe headache by having to think?
I'd go into shock if my remote for the TV stopped working

BTW in your post with a picture on a Mitutoyo caliper I can't open it but I know what you mean.

Take your pick from this lot workshop caliper - Google-søgning

Gordon

Originally Posted by Gordon B. Clarke

C'mon are you really wanting me to get a severe headache by having to think?
BTW in your post with a picture on a Mitutoyo caliper I can't open it but I know what you mean.
Take your pick from this lot workshop caliper - Google-søgning

Hi Gordon,

There was a typo in the URL. This should work:


I don't use other peoples' photos. I always post my own.

- Leigh

A minor quibble is that such things as availability in many sizes and resistance to adverse conditions are listed as pluses for digital calipers, but not for verniers (which are even more resistant to adverse conditions).

As for the future, while most development will surely focus on digital calipers, I think the notion that their accuracy will soon outstrip older types is a bit optimistic. All types require a head that slides along a bar and are subject to wear, thermal issues, deflection, etc.

One practical advantage of some of the older vernier types is that they have been available with large jaws, thus allowing larger diameters to be measured. While there is no reason other types can't have larger jaws (other than cost and more mass to go crunch when they're dropped), this is a practical advantage to some older types.

Cost is also missing as a pro/con. Given the emphasis on digital calipers, much of the cost advantage of older types is now moot. However in long sizes, the verniers still seem to have an advantage.

Perhaps one additional advantage of the digital types is the availability of very large displays, for easier and faster reading (especially for old eyes).

Gordon, I think what Sean the Dog was referring to was what my favorite set has. They have a lock block downstream of the moveable jaw. They have a shaft with a thumb wheel connecting the block and jaw. You open them, lock the block in place and use the thumb wheel to fine feel when the jaws touch. Once adjusted there is no fear of jaw movement while removing them from the part like the standard ones. Very handy for reaching into blind spots where you can't see your dial or digital readout.

Sean the Dog, I hope this is what you meant. I know I wouldn't use the regular(cheapies) for more than checking bolt sizes after having used these for 30 years.

Ben

On edit: Slow typing even after 2 years of training in school gets me every time. Like the ones Leigh showed but the wheel on mine is between the block and jaw with right and left hand threads connecting it.

Leigh and Lazarus, yes that is exactly what I was talking about. We always called them Master Verniers; don't know if there is another name. I had an 8 inch one I wouldn't trade for anything, but it grew legs on me one day. I still miss it.

Used to do a lot of end bells for electric motors and the housings where they fit. When you have a shoulder of maybe 3/16, there is no way to fit a micrometer or inside mic there. These verniers, going up to 48 inches, were all we had that would fit, and the sense of feel was almost as good as a micrometer.

Gordon, you are right about them still being vernier scale readouts and having the same good and bad points as a conventional set, but I do think sense of feel is worth brownie points. I've also used callipers with the little thumb wheel on them. It's really nothing more than a place to put your thumb. Gimmick.