The most popular air meter made here in he U.S. is the ECO, Gilbarco and Romort also made many before they discontinued making them in the 1950s.
I just published a new book titled: Air Meter Identification book. It came out in June. I also maintain a website with a great deal of air meter parts annd literature on it. (
www.petrolianacollectibles.com).
The following was taken from my website:
"Understanding the Model 90 Series ECO
BALANCED INFLATION
First of all, the ECO does not produce air, it only meters it. So many people over the years have asked me, where is the compressor.
It operates by air pressure, not by electricity. When you lift the hose from the hook it opens the mechanism allowing the air to circulate. Once the chuck is placed on the valve stem of the tire, a shot of air is sent into the tire. It then stops and reads the pressure of the tire to see if it the same as what the setting is. If it is not the same, another shot of air is sent into the tire. Each time it does this, the bell rings. It works like this: SHOT....READ....SHOT....READ....SHOT.... It will continue to do this until the pressure in the tire is the same as the pressure that was set on the mechanism. This is what the words "BALANCE INFLATION" on the top chrome piece means."
In the service manual for the Model 90 Series meters there is a long, very detailed explanation of the workings of the meter, but the above is a simple explanation.
By the way, ECO sold many of their meters overseas, I have Instruction Manuals in both Spanish and Japaneese, I don't know if they were sold in Sweden.
If you have any questions about a particular air meter, just email me.
Jack Sim
Author, Gas Pump Identification book and Air Meter Identification book, both can be ordered at:
www.petrolianacollectibles.com [This message has been edited by Jack Sim (edited 09-30-2008).]
