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Topic: Manufacture of precise glassware  (Read 2514 times)

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Offline atom145

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Manufacture of precise glassware
« on: February 10, 2017, 10:07:52 AM »
How are pipettes and volumetric flasks made to have such precise dimensions? And has such precise equipment only existed since mass production of glass or did 19th century chemists also have such equipment? I've made basic equipment like a test tube by glassblowing, but that's a world away from the astonishingly exact equipment in a lab.

Offline Enthalpy

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Re: Manufacture of precise glassware
« Reply #1 on: February 11, 2017, 09:51:49 AM »
[...] did 19th century chemists also have such [accurate] equipment? [...]

My bet is "yes". People already manufactured telescopes, music instruments, clocks for maritime navigation in the 19th century. Even if we don't guess now how they did then, Sapiens weren't stupid and found processes within the available technology. Just like the pyramids were built despite we don't figure out how. Or the Michelson-Morley experiment. And they measured in the mid-19th the precession of Mercury's perihelion despite in 2017 I wouldn't be able to do that.

More generally, hundreds of geniuses accumulated knowledge over generations then like now, and learning a manual manufacture profession takes over a decade. So if presently one singe person, with limited indications about what technology existed then but was lost, thinks for an hour or a decade at an endeavour of the past and doesn't find a method, that's perfectly normal, and brings no indication about the feasibility in the past.

Volume and glassware: even if a diameter wasn't accurate enough, the graduations could be brought afterwards, for instance by filling with water and using scales.

Online Borek

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Re: Manufacture of precise glassware
« Reply #2 on: February 11, 2017, 06:10:23 PM »
even if a diameter wasn't accurate enough, the graduations could be brought afterwards, for instance by filling with water and using scales.

That's the most important part - even if the manufacturing is lousy, it is possible to precisely graduate single volume glassware.

Making a good burette is much more difficult (although burettes can be calibrated as well).

Compare http://www.titrations.info/volumetric-glass-calibration
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline atom145

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Re: Manufacture of precise glassware
« Reply #3 on: February 14, 2017, 12:24:10 PM »
Using a mass of water makes sense. Of course, that leads to the question of how people first made standardised weights...

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