Liquid inside micrometer?

R

Rustypigeon

Plastic

Joined

Mar 3, 2013

Location

PA, USA

• Mar 11, 2013

• #1

Hello. I just bought a used Scherr Tumico 4-5 inch micromter. When I move it I hear a liquid inside the crane. Anyone ever see something like this? Why would the crane be hollow and why would there be liquid inside it?

 

B

bruceec

Plastic

Joined

Mar 26, 2012

Location

Canada

• Mar 11, 2013

• #2

Hi,

The heat of your hand will raise the temp of the crane causing it to expand which will reduce the accuracy of the mic. Most liquids have a high specific heat capacity compared to metals which means they require a larger amount of energy to raise their temperature. By filling the crane with a liquid it will make the temperature more stable (since more energy is required to change the temp.) and the accuracy of the mic will be improved.

Corbin

 

R

Rustypigeon

Plastic

Joined

Mar 3, 2013

Location

PA, USA

• Mar 11, 2013

• #3

Is this a common practice, or just a Sherr Tumico trait? I have never seen it before, then again I have never had a micrometer > 4" before.

 

B

bruceec

Plastic

Joined

Mar 26, 2012

Location

Canada

• Mar 11, 2013

• #4

Hi,

I know it isn't very common anymore if it does exist at all. Most current mics have a plastic insulating piece on the crane that helps to reduce the transfer of heat from your hand to the mic. This is probably due to the fact that the plastic is cheaper and easier to implement.

Corbin

 

R

Rustypigeon

Plastic

Joined

Mar 3, 2013

Location

PA, USA

• Mar 11, 2013

• #5

Do you think it came from the factory like that or did someone modify it? When I google it, I can't find anything on a liquid filled micrometer. It has just peaked my curiosity.

 

B

bruceec

Plastic

Joined

Mar 26, 2012

Location

Canada

• Mar 12, 2013

• #6

Hi,

I am not very familiar with Sherr Tumico micrometers and it may be a modification. I do think the reasoning behind it is sound and if nothing else it is certainly an interesting idea.

Corbin

 

The real Leigh

Diamond

Joined

Nov 23, 2005

Location

Maryland

• Mar 12, 2013

• #7

I expect this is factory-original.

A field modification would require drilling a large hole into the body of the crane, large enough to hold the volume of liquid.
Such a hole (now sealed of course) should be readily apparent.

- Leigh

 

B

Bruce Nelson

Stainless

Joined

Feb 18, 2009

Location

Wisconsin (from May to November); Florida (from No

• Mar 12, 2013

• #8

What is this CRANE that you speak of? Should it not be FRAME?

Lord Byron

 

PixMan

Diamond

Joined

Jan 30, 2007

Location

Central MA USA

• Mar 12, 2013

• #9

Bruce Nelson said:

What is this CRANE that you speak of? Should it not be FRAME?

Lord Byron

Click to expand...

I thought I was the only one going crazy with that. LOL

 

C

christinandavid

Aluminum

Joined

Sep 24, 2012

Location

New Zealand

• Mar 12, 2013

• #10

Must be where BD got the line "If I walk too much farther my crane's gonna leak.."

DP

 

P

PeteM

Diamond

Joined

Jan 15, 2002

Location

West Coast, USA

• Mar 12, 2013

• #11

Of a hundred or so ST mics I've seen, none had liquid filled frames. Haven't seen that as a "feature" in the few Tumico and Scherr-Tumico catalogs I have. Is there any sign of frame damage?

 

R

Rustypigeon

Plastic

Joined

Mar 3, 2013

Location

PA, USA

• Mar 13, 2013

• #12

PeteM said:

Is there any sign of frame damage?

Click to expand...

Other than worn paint from heavy use, I can't find any damage or signs of modification.