A little embarrassed, can't read this outside mic....

[great white]

Well, this is a little embarrassing, but i need a little help reading an outside mic.

A while back I picked up a Starrett 224 outside mic kit. It's an older set, so it's definitely imperial.

But looking at the barrell, I can't seem to understand the markings.

They look like so:




I'm used to a set of horizontal lines to figure out the last digits, but this doesn't have them. What you se eis the total of the measurement markings (well, except the interchangeable anvils for different inch measurements).

How do I properly read this mic?

Apologies for the simplistic question, but I just can't seem to figure out how to read this type of dial.....

 

[woodchucker]

Looks to be about. 0252 or . 0253

 

[great white]

Looks to be about. 0252 or . 0253

I'm looking for how to read it, not just what it says. It's an older model and I'm guessing I just haven't been exposed to it before.

Well, or I simply forgot......happens more and more these days it seems.

 

[woodchucker]

So each line on the inner barrel is 25 thou.
Add what the outer barrel says. In this case about2 tenths

 

[Flyinfool]

As told to me by a wise man, the only dumb question is one you already know the answer to.

On the stationary part of the barrel there are lines, each line represents 0.025 inch.
If you had it open a bit more there are markings every 4th line to indicate 0.100.
On the moveable part of the barrel the lines each represent 0.001 inch.
So first you look at the big graduations, then count how many small graduations and add that all up.
Now you look at the graduations on the movable part and count how many and add that to the first number. that is your total measurement.

Once you get some practice you will be able to estimate where you are in the area between lines to get to almost 0.0001 resolution.

Start by checking some things of a known dimension to get some practice, there is some definite technique to be learned to get accurate consistent readings.

 

[mmcmdl]

.0253 looks to be correct as long as the mic is calibrated .

 

[great white]

This is still going over my head for some reason. I'm used to marks lining up, not "guesstimating" where the between line lay....

 

[mmcmdl]

This is still going over my head for some reason. I'm used to marks lining up, not "guesstimating" where the between line lay....

If you close it to the line where the zero lines up you're at .025 . You are 2-3 tenths shy of it . .0252 or .0253 would be correct . Last time I worked in tents was with the Cub Scouts .

 

[great white]

Here's more of the barell opened up to show more divisions:




This is obviously an older design. I'm used to mics with horizontal lines on the sleeve that will align with one of the barbell numbers to give you the last digits to add to the larger measurement.

I must be a little stunned today or something as even the online pages i google don't seem to fit this marking system.....

 

[mmcmdl]

.1525 . Have you been celebrating the holiday today ?