Like you say Zero board feet is none existent. You cannot measure what
is not there. However,...
LOL, There is a negative board foot and no doubt you have seen it many
times. Ever pick up a piece of wood to use only to find out it is a
1/2 " too short, or 6" to short?
Barometric pressure is relative, and a far different usage. It is also
useful for altitude measurement.
Then here you now go into Temperature? There are a couple scales
alright, degF and degC then there is a scale from absolute 0 wherein
there is no molecular movement. But what is the point?
1 atmosphere equals 29.92 " hg positive pressure, not a vacuum.
.000024583 atmosphere equals .010 "hg positive pressure, not a vacuum.
As I have been saying, a vacuum is relative. There is in reality no
such thing as less than O PSI absolute.
You can never achieve 30" HG barometric pressure unless you use a
cheap gauge 29.92 is the best you can do, and it is not a vacuum.
but it was nice of you to explain why and how a vacuum is relative in
your next to last paragraph. So can we consider this subtopic closed?
No, 0 psi is absolute. Vacuum is always relevant.
The standard atmosphere (symbol: atm) is a unit of pressure defined as
101325 Pa (1.01325 bar). It is sometimes used as a reference or
standard pressure. In 1954 the 10th Conférence Générale des Poids et
Mesures (CGPM) adopted standard atmosphere for general use and
affirmed its definition of being precisely equal to 1,013,250 dynes
per square centimetre (101325 Pa).
Therefore 1 atm is equal to 14.69595 psi
There is no such thing as a vacuum, per se' it is always a relative
At 250,000 feet above sea level it is 0 PSI Absolute. Imperial
Using a moisture indicator on any wood, it would register "0"
Microns is also used in measurement of a vacuum to tell when certain
physical properties are no longer there.
The tire pressure gauge reads 0 PSIg "g" is for gauge pressure. Not
Look at a low side refer gauge sometime. "0" on it is the divide
between PSIg and hg
Well I was making a pitiful comment about wood to try and bring this
around, back to wood, then I unfortunately through in the comment
about microns used to gauge vacuum below a certain point for the
purposes of ridding systems of H20 and other properties. Which I knew
you would be clueless about. That was stupid of me and I am sorry.
So, please forgive me, and lets get back to WW'ing or should we be
going to some gym and duke it out? LOL
What you said brought back memories, old ones. Like the vacuum gauge
in inches of water column. Trying to use it for economy runs to save
gas for a race. Watching that sucker jump around made it all
pointless. In order to set injectors, or multiple carbs you had to use
a manometer to sync them up. On motorcycles and their smaller engines
and High rpms it was cortical, if a valve failed to seat or your fuel
system flooded out, it was a definite boom time in the intake
manifold. I've had more than one engine go up in flames, especially
with stromberg 97's. ;)
that's ok, I meant it as a joke, "in my imagination" just letting it
go wild to conjure up something. I believe that was first in response
to Mikes comment on using imagination. Guess it didn't come across
that way, sorry.
I've had that happen with skil saws, actually had glowing embers from
a dull blade.
As long as he doesn't ask for money too. :)
I finally picked up an 1 1/2" hose for some of my small stuff, then
realized I should cut that into smaller pieces and buy a few more
fittings for it. I mistakenly had my hand holding the 2 1/2 hose when
I hit to button to start the vac and boy did that hurt. that flex hose
slammed closed in a hurry, pinching my skin and gave me instant blood
blisters with that small hose hooked up. WOWEE! Then the small hose
started whistling and stuff. I'm not sure how long that hose is, but
it is so restrictive that I want to shorten it some to increase the
air flow and cut down on the whistling at the same time. I'm thinking
I am going to Rockler for those. they seem much better prepared with
the fittings and hose then woodcraft where I picked up the hose on a
whim. Where I am at there is only a woodcraft, and it is an
independent store. Rockler is about 50-60 miles away.
Broken record or not. There is a very low probability of people being
stuck by lightning, but they are. There is a very low probability of
people being struck by a meteorite but there is a recent story in the
news about that happening.
There is a very low probability of a person being killed by a falling
tree, but there are people who are cutting down their trees every day so
they do not fall on them and kill them.
Low probability means exactly that, it can happen but infrequently.
Remember Murphy's law. Why tempt Murphy.
The point is, there's a low probability in everything. If you want to
worry about everything that is technically "possible" happening to you,
go for it. Enjoy that life.
That's the kind of severely flawed logic that inhabits the brains of
people who will never fly on an airplane but have no problem driving on
the interstate, even though the chances of injury or death are almost
unbelievably, exponentially higher when driving a car.
If people want to live in fear of everything that "might" or "could"
happen to them, well... let's just say they make lots of pills for that
"Playing is not something I do at night, it's my function in life"
There is a difference between worrying about the probabilities of
accident, and taking steps to avoid a potential for an accident. You
do not spend a lot of money installing things to prevent an 1 in a
million probability of accident. However you don't ignore the
possibility that it can happen. Sort of like walk under a ladder, the
probability of something falling off of the ladder is remote, it is just
good practice not to get in the habit of doing it.
There are other places where this applies. You buy home owners insurance
even though there is a small probability that your house will be damaged
or broken into. You make sure there are not children in the area where
you are mowing even thought the probability you will hit something that
will fly our and hit a child. Most people modify there behavior or
make purchases based on low probability events.
I simply don't worry about it. There are numerous other things in the
shop that make sparks and on a continuous basis. Like "any" electric
tool or machine that has a universal motor. Yes damn near any hand held
power tool. ;~)
You have worried about the excessive collection of dust in your shop,
and ALL of the problems that it may cause. You have installed a dust
collector so the dust is controlled and diverted to safe areas.
No I have not worried about excessive dust in the shop. I once buried
my choc Lab under a pile on the out feed side of the planer. She was
not worried either. ;~)
I got a dust collector because I got sick and tired of cleaning up and
tracking dust into the house. I absolutely did not worry about any
dangers other than breathing in that stuff. And again FWIW I was
commenting about a spark creating an explosion not excessive dust or any
other problems that it caused other than a mess.
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