Do you have to “zero” a new micrometer?

[Runs With Scissors]

So my “calibration regimen" is basically non-existant…….

I wish I could clim some "high ground" when it comes to calibrating my ‘precision tools’ , but alas, I can’t.

But I just bought a new (actually brand new….not just “new to me” new)1-2 inch Mitutoyo micrometer, that they claim is accurate to the .0001 position.

Well, when I measure the “standard” they sent with it, it's off by about .0003”.

Now .0003” is probably way more accurate than I could ever do, but it’s kinda bugging me.

In the box they sent a “mini-spanner” wrench that fits the mic,

I read through the “manual” and although they address “safety” and cleaning…..(In Klingon, as well as 534 different other languages ), they make no mention of why the spanner wrench is included.

I saw a video where a person is using the “mini-spanner” wrench to take off the handle and “reset” it.

It makes sense (kinda), but I don’t want to “jack up” my new mic.

Has anyone had to do this?

 

[Hugo Habicht]

Yes, you are right, you can zero it with this small "spanner".

 

[Sidekick]

Let the temperature stabilize for a couple days then set. Did they supply a certificate for the pin?

 

[TheOldHokie]

So my “calibration regimen" is basically non-existant…….

I wish I could clim some "high ground" when it comes to calibrating my ‘precision tools’ , but alas, I can’t.

But I just bought a new (actually brand new….not just “new to me” new)1-2 inch Mitutoyo micrometer, that they claim is accurate to the .0001 position.

Well, when I measure the “standard” they sent with it, it's off by about .0003”.

View attachment 168799


View attachment 168800


Now .0003” is probably way more accurate than I could ever do, but it’s kinda bugging me.

In the box they sent a “mini-spanner” wrench that fits the mic,

View attachment 168801

I read through the “manual” and although they address “safety” and cleaning…..(In Klingon, as well as 534 different other languages ), they make no mention of why the spanner wrench is included.

View attachment 168802

I saw a video where a person is using the “mini-spanner” wrench to take off the handle and “reset” it.

It makes sense (kinda), but I don’t want to “jack up” my new mic.

Has anyone had to do this?

Anybody that owns a micrometer has to do this. The micrometer is just a 100 TPI lead screw that will wear (unevenly) over time and the graduated collar on the barrel can slip necesitating recalibration

The spanner is used to unlock the collar on the barrel so you can rotate it to zero the reading. Then you lock it back.

I hate those standards and use a 1-2-3 block to recalibrate mine.

Now the bigger question. Do you understand the difference between absolute and comparative measurement?

Comparutuve measurements usung the same instrument are not affected by calibration. If you need +/- .0001 accuracy for absolute measurements you need to start practicing your touch on the instrument and thinking environmental conditions in addition to worrying about calibration.

Dan

 

[mikester]

Buy a calibrated micrometer with a NIST traceable certificate if you want to be sure you have a measurement device that gives you standardized measurements. Work in a climate controlled shop kept at standard temperature and pressure.

 

[Lil Foot]

Before using the spanner to reset, make absolutely sure that the ends of the reference standard and the anvils of the micrometer are CLEAN.
After a solvent wipe down to remove any rust protection, place a CLEAN piece of paper (typing or copier) between the reference and the anvils, close LIGHTLY, and pull the paper through.
Repeat a couple times.
Only when you are sure the faces are clean, consider changing the zero setting.
And don't change the zero with the mic closed- open it, move the appropriate amount, and re-check.
Technically, for ultimate accuracy, it should be done in a certified controlled temp environment, but stabilizing it in the environment where it will be used the most is good enough for home/hobby use.

 

[William1]

When I used a mic all day, I'd zero it multiple times. Often a light rap on the butt (or over tighten to move the opposite direction) zero'd it just fine. I never used a 'standard' to set it, always set to zero. If zero'd, then you can check and see if the 'standard' is right.....

 

[Yooper]

What is the temperature? We are in the middle of a deep freeze and a micrometer from a cold bench would show that.

 

[TheOldHokie]

When I used a mic all day, I'd zero it multiple times. Often a light rap on the butt (or over tighten to move the opposite direction) zero'd it just fine. I never used a 'standard' to set it, always set to zero. If zero'd, then you can check and see if the 'standard' is right.....

How do you set a common 1-2" micrometer to zero without using a standard?

Dan

 

[85Hokie]

I use a dial caliper at work, after cleaning the open jaws - I often have to reset ZERO based on if the workshop is 20 F or 70 F - now it is only off by a little, nothing as precise as the micrometer that you are referring too, but still has to be reset. +/- .001 or so

 

[TheOldHokie]

Buy a calibrated micrometer with a NIST traceable certificate if you want to be sure you have a measurement device that gives you standardized measurements. Work in a climate controlled shop kept at standard temperature and pressure.

That cert is multiple generations removed from the NIST artifact. The accuracy of any instrument is only as good as the OEMs quality control.

Once you take that instrument out of the box you might as well throw that cert in the trash. The only practical way to gaurantee accuracy once you buy an instrument is regular calibration using a known good artifact - e.g standard. A medium quality set of .00005 gage blocks will set you back about $200 and will let you calibrate micrometers to +/- .0001

Dan

 

[ken erickson]

The micrometer is just a 100 TPI lead screw that will wear (unevenly) over time and the graduated collar on the barrel can slip necesitating recalibration

Just a small correction, A standard imperial micrometer's screw is 40 TPI.

 

[lynnmor]

I bought a new Mitutoyo 1-2 micrometer about 50 years ago, the only thing wrong was the standard, I guess they will never learn. Yes, you need to check the calibration regularly.

 

[lynnmor]

Before using the spanner to reset, make absolutely sure that the ends of the reference standard and the anvils of the micrometer are CLEAN.
After a solvent wipe down to remove any rust protection, place a CLEAN piece of paper (typing or copier) between the reference and the anvils, close LIGHTLY, and pull the paper through.
Repeat a couple times.
Only when you are sure the faces are clean, consider changing the zero setting.
And don't change the zero with the mic closed- open it, move the appropriate amount, and re-check.
Technically, for ultimate accuracy, it should be done in a certified controlled temp environment, but stabilizing it in the environment where it will be used the most is good enough for home/hobby use.

I know that you know that the micrometer will gain heat from your grubby hands so it should be insulated from them with a cloth. No point in having controlled temperatures when hands are warming it many degrees.

 

[TheOldHokie]

Just a small correction, A standard imperial micrometer's screw is 40 TPI.

Yikes - that was a major senior moment wasnt it

Dan

 

[ken erickson]

Yikes - that was a major senior moment wasnt it

Dan

Dan,
If thats a major senior moment for you, me being 69, I am in TROUBLE! LOL.

 

[TheOldHokie]

Dan,
If thats a major senior moment for you, me being 69, I am in TROUBLE! LOL.

I am beyond salvaging but you still have hope

 

[Lil Foot]

 

[PoTreeBoy]

I am beyond salvaging but you still have hope

View attachment 168814

What! And deprive him of all the fun?

 

[William1]

How do you set a common 1-2" micrometer to zero without using a standard?

Dan

Tap (or if past zero, tighten) to move the slip barrel. It's right when closed, it zero's.