discussed in several publications putman harpster both supra f maner et al u201c performance enhancement with remote monitoring of condenser air in leak u201d power gen 99 americas conference proceedings f maner et al u201c performance improvements based on measurement and management of air in leak u201d 1999 epri condenser technology conference charleston s c aug 30 31 1999 special focus is directed to the water to air mass ratio harpster supra because of its generally clear indication for relating the threshold of air in leakage to the onset of excess condenser back pressure the instrument accuracy for measuring air in leakage is about 1 scfm with a precision of 0 1 scfm when calibrated for a wide dynamic range it was this instrument that allowed well defined property measurements of gas in the vent line to permit precise quantification of subcooling within the condenser subsections and the identification of gas dynamics inside the condenser described herein to understand the behavior of a condenser under the influence of air ingress one must first understand its behavior without air and other non condensable gases this view permits the luxury of examining a very simple hypothetical configuration without the complexity of obstructions and an air removal section ars this hypothetical condenser 20 is shown in fig4 it would be a somewhat practical design if there were no air in leakage or if there was no production of other non condensable gases developed in the water and steam cycle since all of the load could be condensed and a vacuum maintained assume a hexagonal patterned obstruction free tube bundle 22 of radius r 12 37 ft containing n t 20 272 tubes not all shown of 1 inch outside diameter 22 ga wall located on 2.