Storage of precision levels

[Dennis WAParticipant @denniswa]

I have a precision engineers block level made by Cooke Troughton and Simms. I got it from a now-deceased friend who had worked for them for many years. He was what we would call today an Instrument Technician.

He told me to always store it vertically (in its box) so that the bubble in the vial was at one end (out of sight) and not to store it horizontally so that the bubble was where you would normally see it when using the level.

I imagine that this way the bubble forms an air-pocket next to the tip of the vial where the seal is. Why would he have recommended this?

[Dennis WAParticipant @denniswa]

[Jeff DaymanParticipant @jeffdayman43397]

Hi Dennis,

 

I was taught the same method for storing levels. It was explained to me that if impurities in the liquid or precipitates from the dyes used should ever stick to the glass and form a ridge or “bathtub ring” or film, it was better to have that happen at the ends. If these ridges or rings or film formed in the centre where level is read, it could affect the accuracy of the reading. The ends are usually not visible so any debris there is harmless. I was also told that in the very early days of such levels the liquid to bubble joint would sometimes etch or erode the glass lightly, so that was another reason to keep the accurate area wetted when not in use.

 

May not be the absolute gospel but that is what I was taught many moons ago.

 

JD

[Clive HartlandParticipant @clivehartland94829]

In all my time as an Instrument tech ( 60 years now) I have never heard of that!

Instruments with liquid bubbles have always been stored horizontal apart from some Cooke Troughten and Simms and a couple of Hilger and watts levels in metal cases.

All others only have a storage attitude because of the design of the case they are in.

 

Clive

[Dennis WAParticipant @denniswa]

Jeff & Clive…..Thanks for your replies.

 

Any other input?

 

Merry Christmas!

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, I have never heard of precision or any other type of bubble level to be stored in the vertical position, nor do I know of anyone who ever has. That does not mean it isn’t true, however, you could argue that storing them this way is detrimental to a glass vial, because glass does actually creep minutely over time and can cause an unbalanced distortion in the vial, whereas if stored horizontally any creep distortion would be balanced about the mid point. Picking at straws a bit I know.

 

As far as as etching the glass, well! the only thing I know that etches glass is hydrofluoric acid, and you wouldn’t want that anywhere near yourself let alone your precious tools. Staining or “bathtub ring” could be a problem perhaps, but most good precision levels use a clear liquid of very good purity, so staining from dye precipitation should not be a problem.

 

Regards Nick.

 

Seasons greatings to all.

[gerry maddenParticipant @gerrymadden53711]

I have a 1970s aircraft periscopic sextant. The original case has two big red labels. One shows the orientation for ‘airplane stowage’ and the other for ‘ground stowage’. The latter is horizontal. I always wondered why….

 

Gerry

[Sub MandrelParticipant @submandrel]

I imagine that when its on an aircraft the vertical orientation helps stop the bubble from being broken up by vibration.

 

Neil

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