It was introduced by Parker in 1948, as a new filling system adopted on the 51 in place of the previous vacumatic. Actually for the operating modes this system is very similar to the sleeve filler used by LeBoeuf, because it is based on the pressure of a rubber sac to be made by a side opening on the metal cylinder that contains the same, which is accessed by unscrewing the pen body from the nib section.
Unlike the classic sleeve filler the aerometric filler however provides for the presence of a breather inside the system, which requires to repeat the pressure of the bar four or five times (as shown on the instructions engraved on some of them) to complete the loading. It can therefore be interpreted as a fusion between a sleeve filler and the previous vacumatic filler.
The name aerometric is actually used in this sense mostly by collectors, the company was rather referring to it by the name Aero-metric Ink System (reported for example in advertisements like this) for the set of the filling system (called Foto-fill filler), the feeder and the new PVC tank (called Pli-glass), which allowed the company to proclaim the pen as not containing any rubber parts.
- Patent n° US-2612867, of 1952-10-07, requested on 1948-08-23, of Marlin S. Baker, Harlan H. Zodtner, The Parker Pen Company. Fountain pen.