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Posted by Neil Smith [MVP Digital Media] on 09/30/28 11:38
On Sun, 29 Jan 2006 19:46:43 GMT, "doc" <doc@drdimento.net> wrote:
>i stand corrected. thanks for the info. however, unless the tape is kept
>at 300+ degrees for the lowest i read being mercury, then it wouldn't be
>evaporated right?
Wrong again. A vapour is formed when a component's vapour pressure
exceeds that of the ambient pressure. So, by reducing the pressure way
below atmospheric pressure, you can get a metal to 'boil' far far
below what you'd think was it's boiling point.
Even more interestingly, metals and other solids have a small but
finite vapour pressure even at room temperature. So if you're say 80%
of the point where a substance would 'boil' at a given temperature,
there's an increasing likelihood of significant amounts of vapour in
the area.
HTH
Cheers - Neil
>drd
>
>"Neil Smith [MVP Digital Media]" <neil@nospam.com> wrote in message
>news:q10ds151n71tlq28ii45d14o3gig98g9np@4ax.com...
>> On Thu, 12 Jan 2006 15:23:41 GMT, "doc" <doc@drdimento.net> wrote:
>>
>>>hmmmmm, "evaporated metal" - - metal doesn't evaporate. it oxidizes but
>>>it
>>>can not evaporate. would take 5000 degrees.
>>
>> Bloody nonsense, way lower - and all metals can be made to evaporate
>> (apart from one or two semi-metals at ambient pressure, which sublime)
>>
>> Check out your facts before posting again : Here are some exxamples of
>> "facts" :
>>
>> http://www.noblemind.com/search.exe?keyword=Barium+Boiling+Point&var=2
>> http://www.noblemind.com/search.exe?keyword=Mercury+Boiling+Point&var=2
>> http://www.noblemind.com/search.exe?keyword=Lithium+Boiling+Point&var=2
>> http://www.noblemind.com/search.exe?keyword=Zinc+Boiling+Point&var=2
>> http://www.noblemind.com/search.exe?keyword=Lead+Boiling+Point&var=2
>>
>>
>>>drd
>>>
>>>"webpa" <webpa@aol.com> wrote in message
>>>news:1136568384.291913.175010@g47g2000cwa.googlegroups.com...
>>>> Sorry. I was forced to stop reading your essay when you described
>>>> "oxide particles" on DV tape. AFAIK, there is NO oxide coated (miniDV,
>>>> DVCPro, etc) tape. It is all coated with a film of evaporated metal
>>>> (among other things).
>>>>
>>>
>>
>
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