# Vaccuum at home.

1. Nov 3, 2007

### Anekdot

I am curious how cam i make vacuum at home without having any sophisticated hardware.
Not asking for 100% vacuum just 75+% at least.

2. Nov 3, 2007

### ZapperZ

Staff Emeritus
What are 100% and 75% vacuum?

Zz.

3. Nov 3, 2007

### Anekdot

100% empty of matter. I dont mean precicly i need 75+% vacuum i just ment it must be as empty as it possible can be made at home.

4. Nov 3, 2007

### ZapperZ

Staff Emeritus
No one has achieved 100% "empty matter". That still doesn't tell me what "75%" is. What vacuum level do you want in terms of the pressure?

Zz.

5. Nov 3, 2007

### Anekdot

Okay forget about all % just best vacuum i can get at home, i really not shysicist and not really aware of vacuum characteristics like pressure, i need pressure to be about same as in space vacuum.

6. Nov 3, 2007

### ZapperZ

Staff Emeritus
Then it is not possible using what you wanted.

Zz.

7. Nov 3, 2007

### Anekdot

What would be the cheapest way to make it possible?

8. Nov 3, 2007

### ZapperZ

Staff Emeritus
A stainless steel, clean vacuum chamber, a combination of scroll pump, turbo pump and/or ion pump/cryopump, heating tapes, and lots of clean, UHV-approved (ultra-high vacuum) clean gloves for handling inside-vacuum parts, and maybe, just maybe, you'll get to 10^-10 Torr.

Those are not "cheap", and certainly doesn't cost less than $50,000. And I haven't included the cost of the controllers for those pumps yet and vacuum connectors/pipe, and flanges. And when I said "clean vacuum chamber", I mean clean with citrinox in an ultrasonic bath. Zz. 9. Nov 3, 2007 ### Anekdot I only got 100$ for this, what vacuum i can make for this?

10. Nov 3, 2007

Using just an ordinary rotary pump (essentially the same type of pump that is used to pimp e.g. water) you can get down to less than a 1/1000 of atmospheric pressure. However, even a rotary pump is more expensive than $100. If you just want to play around with low pressures you can always just try pumping with something else. Even a vacuum cleaner can be used to create a "vacuum", albeit a very bad one. 11. Nov 3, 2007 ### ZapperZ Staff Emeritus .. or one can just suck on a straw.... Zz. 12. Nov 3, 2007 ### Gokul43201 Staff Emeritus You can get about 28" Hg (better than 90% vacuum) with a cheap venturi pump. If you look around, you might find a cheap, used one for$20 or so.

13. Nov 3, 2007

### cesiumfrog

75%? Is that like, remove three quarters of the air from a vessel? Probably doable.

The cheapest way to make a fun vacuum is like this: take an empty coke can, put a tablespoon or so of water in, hold it over the stove until it is boiling (the idea here is to fill the can up with water vapour, displacing all of the air), then [using long tongs, etc, your safety is your concern] lower the can upside-down into a sink-full of cold water. As the water vapour condenses, the can will be crumpled in a bang.

Another related method is just to take a long tube of some liquid, and invert it into a reservoir, like a mercury barometer (it works best with such a dense and low-volatility liquid).

A cheap pump will probably make a good enough vacuum for you to make marshmallows "breath". A lot depends on what you actually want the vacuum for.. I remember studying electric discharges in high school but being unable to produce our own cathode ray tubes. Makes me wonder how original cathode ray experiments were evacuated... but I presume it's only the modern cutting edge work that requires such expense to replicate.

14. Nov 3, 2007

### f95toli

I suspect CRTs are evacuated using the same method as vacuum tubes, i.e. using a getter (e.g. barium).