Vincent said:
Our company intend to build a clean room with possitive pressure in the
room.We will install a blowing fan to suck the air from outside into the
clean room with the damper control.
Can anyone know how to meassure the pressure different between inside and
outside of the clean room.
With a manometer.
You can buy a sensitive differential pressure guage that will do the same
thing.
In those circumstances, pressures are measured in INCHES of WATER.
SO: if you want to go the DYI route you pick a location where you want to
monitor the pressure and you bring tubes from INSIDE the enclosure and
OUTSIDE the enclosure. You connect these tubes to a U shaped glass or
plastic (transparent) section of tube with arms on the order of 10 to 18".
Before connection you put some WATER in the tubes to fill each arm about 5".
When you complete the connection the DIFFERENCE between the water level in
each side of the "U" is the pressure inside your room.
You can buy "scientific" versions of the above thay feature a large (very)
diameter tube on one side and a sloping tube on the other side. For
pressure differences of a fraction of an inch, the sloping tube permits a
more accurate measurement.
But, basically, all you need is some clear tubing, a ruler, and some water.