What instrument will I use to measure this pressure?

Question

What instrument will I use for this scenario? "There are two rooms which are separated by a door... The first room is the Mall and in the other room is to the hotel... In the first room there is a good supply of Air coming from A/C...so when the door opens there is a vacuum coming from the second room that causes the cold air from first room to be sucked by the second room... So how can I measure the pressure from the second room when the door opens? Because I need to get How much air has been transferred when the door opens... Thnx

Answer 1

Good old fashioned trig and geomatry (spell check?) so your tools are numbers, paper and pencil, perhaps a computer, and really smart person.

Answer 2

You won't be able to reliably determine the quantity of air that shifts because you are dealing with a chaotic dynamic.

You will be able to determine the NET amount of air that has shifted only. You will also only be able to tell this assuming a completely closed system (i.e. 100 percent insulation). Your measuring tool could be a barometer, however - you also need to understand that the "volume" of the air will also depend on the temperature of the mix, and there is something that you'd only be able to tell if both rooms were in perfect thermal stasis and insulation.

Realistically, it is impossible to know the exact answer to your question. The best you can hope to do is approximate.

Answer 3

Measure the pressure in both rooms with the doors closed, then measure it again with the doors open.

Or, you could use one of these air flow measurement meters:

Alnor CompuFlow 8570 air velocity meter quickly measure velocity, volume and temperature. The air velocity meter does not store data. A 42’’ articulated probe allows readings in even the most inaccessible places.

CompuFlow 8585 Air Velocity Meter
Alnor CompuFlow 8585 thermo-anemometers measure velocity, volume, temperature, humidity, dewpoint, and wet bulb. The 8585 can print in real-time to a MicroPrinter or download to a computer. Over 1500 readings or datalogs can be stored on an 8585 before downloading. The 42-inch articulated probe makes measuring face velocity at a fume hood or taking flow readings in a duct easy.

Taken from: http://www.muellersales.com/test.html#air

Answer 4

Well, one instrument for measuring small pressure differences is a manometer ( http://www.dwyer-inst.com/htdocs/pressure/ManometerIntroduction.cfm ) but the "greeneyeddevil" had a good description of why simply knowing the pressure differential is not enough to determine the volume of air transfered.