The mirror is supported by three air bags. To supply air pressure for these bags a pneumatic system is used. The nasty problem of all pneumatic systems is that whenever you compress air, you bring in water and most of the complexity in the above is an attempt to remove it.
At the bottom of the tank there is an electric automatic condensate drain that drains the bottom of the tank every few minutes for about two seconds to get rid of water that get trapped there.
Then there is a regulator on the tank which controls the line pressure. Currently I have this set to 40 PSI for no particular reason.
In the lines there are two Norgren filters to trap water. One is downstairs near the compressor, the other is mounted on the pier of the telescope. These are supposedly automatic and will dump the water on the floor automatically. They also seem to be capable of manual operation by pushing the white tube on the bottom upward. They also have a colored plug on the top; if this plug is red, the filter should be replaced.
On the telescope pier there is a Parker manual filter after this as a filter of last resort. It can be drained by screwing the screw on the bottom counterclockwise.
Next to the Parker filter is a Fairchild Precision Regulator that adjusts the pressure to the bags. This unit has a large pressure gauge mounted on it. I haven't the faintest idea what pressure to set it to. I have set it to 5 units.
Finally there is a manifold on the telescope. It must split the air into separate lines. There is a pressure meter on it that reads inches of water. Right now there seems to be a awfully large pressure drop between the two. Remember 1 PSI is 27.6 in of water.
