# Calibrating a precision level



## DPittman (Nov 19, 2022)

I've had a nice little Starrett precision level for a while but acquired a larger  "J Rabone & Son's Made in England" level awhile back.  Unfortunately the larger level had the vial busted out and was dirty, a bit rusty and rough looking.  I ordered a replacement vial from Aliexpress and didn't really comprehend the claimed accuracy specifications (.02mm/meter) of the vial at the time. 
I have had one heck of a time calibrating it and I believe about half the trouble was my own dumbness in incorrect adjustments as it can be confusing.  The other challenge I believe is because the vial is S0 sensitive and likely more sensitive than I should have ordered. I think there were .05mm/meter vials available and they were a bit cheaper also.
I repainted the base with some black wrinkle paint, cleaned up the chrome tubes the best I could, slid a white business card underneath the vial bottom and used plaster of Paris to hold the vial in place. It's not as nice as the newer Starrett but it was destined for the junk but now is useable.


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## Degen (Nov 19, 2022)

Years ago I was taught to repair masonry levels used in the concrete forming industry (vials get broken when they get dirty and cleaned not to gently.  While the body of the level is good the vial is toast.

So vials are a dime a dozen (compared to the cast level body), so replacement it is.

I was taught to use glazing putty (or plumbers putty in a pinch) as it sets over a couple of days and doesn't soften like plaster does if damp.  The second item is it allows you to tweak the vial before it sets.


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## DPittman (Nov 20, 2022)

Here is a short video that shows the extreme sensitivity of my newly fixed level.  The Starrett #98 is the little guy sitting beside it.  They are both sitting on my shop bench which is a VERY sturdy platform, 3/16" plate steel over solid 2x6 top.  There is no noticeable movement or flex to it with out the level to indicate such.  I am pressing firmly with my finger on the top and do not believe it is a temperature change effect I am seeing as it is so quick acting? I'm afraid of trying to use it to check the level of my lathes as I think I will never be able to get things "level".


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## Degen (Nov 20, 2022)

DPittman said:


> Here is a short video that shows the extreme sensitivity of my newly fixed level.  The Starrett #98 is the little guy sitting beside it.  They are both sitting on my shop bench which is a VERY sturdy platform, 3/16" plate steel over solid 2x6 top.  There is no noticeable movement or flex to it with out the level to indicate such.  I am pressing firmly with my finger on the top and do not believe it is a temperature change effect I am seeing as it is so quick acting? I'm afraid of trying to use it to check the level of my lathes as I think I will never be able to get things "level".


View your own video.  You will see both bubbles move.  On the small level approx 1/2 a div. on the large almost 3 div.

Using the large allow yourself 1 div of variation.

BTW your table is flexing and you  levels show it.


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## DPittman (Nov 20, 2022)

Degen said:


> View your own video.  You will see both bubbles move.  On the small level approx 1/2 a div. on the large almost 3 div.
> 
> Using the large allow yourself 1 div of variation.
> 
> BTW your table is flexing and you  levels show it.


Yes I saw that but the difference between the two is significant.  And yes I know the table is flexing that's why the bubble is moving.


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## Tom O (Nov 20, 2022)

Keith Rucker did this video.


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