1. there are diferent paths to learning, some are more efficient then others, the whole "school is a waste" mind set is ignorant to say the least. I know there are some great techs with little to no book learning, but they are the exception not the rule.
do not tell me i wasted my time in school, after i give you information I aquired in school!

things are quiet here today so I guess i am stiring the pot!

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Micron is part of the Metric System. There are 1,000,000 microns in a meter. When you do the conversion of inches to microns, there are about 25,400 microns in an inch.

When you start a vacuum you have 29.92 inches of mercury absalute pressure. When you get down to the last inch of pressure it is divided into 25,400 units for the sake of measuring such a low vacuum.

3. Originally posted by richlaf
Micron is part of the Metric System. There are 1,000,000 microns in a meter. When you do the conversion of inches to microns, there are about 25,400 microns in an inch.

When you start a vacuum you have 29.92 inches of mercury absalute pressure. When you get down to the last inch of pressure it is divided into 25,400 units for the sake of measuring such a low vacuum.
Nice explanation. The J/B Industries link has the most concise explanation I've seen regarding a vacuum.

4. its not as much about "dumb questions" as basic common sense

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Boil, Boil, Toil and Trouble.

6. ct2
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So now all you need is a gauge that reads in 1/100's of an inch.

I have a micro meter that reads in 1/100ths of an inch. at least thats what the big lines are

7. all my experience is a combination of my school and fieldwork and frankly my successes and mistakes.. I consistently am learning still having to re-certify and keep up with the advances in the field.

However I found more people here on this site who are professionals in this field are for most part gracious with their experiences and knowledge than anywhere else I have looked...

Glad I found it and glad to have been able to join up and contribute in some small ways if able to.

8. Moved this old thread to Tech to Tech.

9. I have a question: what's the difference between 500 microns and 1000 microns at that scale? Why is 500 microns the standard for pulling a vacuum on a system?

10. How did we end up in a thread from 2005?

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I'd Pull to 200 Micron's - Hold for 1/2 Hour , Pressure it to 250 PSI Nitro
Pull again to 100 Micron's Hold for 1hr , Pressure Pressure it to 300-350 Psi
Pull again to 50 Microns Hold for 3 Hrs. - still - OK then I Call it ans Release - this being on a Mini Split as those Lines
are Weak and Long on 2 Head & 3 Head Systems . ( I'd Speed it Up ) or have 2 Pumps for 3 Head System - I Guess ? ~ seeing there is No Main Manifold ? Or do You Guys seeing the
Coil as only having 1 Full Complete Internal Line Make Up ? seems 3 Heads system would taking Long Time ..Otherwise I have 3 Head Unit coming up in week and have No
Idea on Internals Gree which has Mitsubishi Compressor .

12. Thanks for reviving a 14 year old thread and a 3 year old reply

13. Isn't that the point of archiving them all? As a reference for people who weren't looking in 2005 - but who have the same questions now?

PHM
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Originally Posted by rcstl
How did we end up in a thread from 2005?

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