Though Pauling was officially assigned to Division B upon induction into the NDRC, he was not limited to work with propellants.
Less than a month after joining the NDRC, Pauling was already in contact with researchers outside of his division. Even as
he began work with explosives, he was analyzing other projects and departments.
On October 3, 1940, Pauling met with W.K. Lewis in New York City. There, Lewis told him briefly of the need for an instrument
capable of measuring the partial pressure of oxygen. He explained that soldiers operating in low-oxygen environments - primarily
airplanes and submarines - had long been fearful of unchecked oxygen depletion which could, in extreme cases, lead to loss
of consciousness and death. An oxygen meter would allow pilots and submariners to track oxygen levels within the cockpit
or submarine cabin, allowing them to adjust for dangerous decreases.
The following day, Pauling met with Wendell Latimer and Thorfin Hogness, fellow members of the NDRC. The two men, who had previously visited naval bases on behalf of the committee, discussed the
importance of the oxygen meter with Pauling, assuring him that it would be a significant tool for victory in the war. The
following day, Pauling began mentally sketching out plans for the instrument. Before long, he had struck on a possible design.
On October 8, he sent a telegram to NDRC administrator James Conant stating that he had a "most promising" means of determining
partial pressure. Soon after, Pauling received an unofficial order from Harris M. Chadwell, Conant's right hand man, to begin his research.
Pauling promptly wrote a short letter to Conant describing his plan for the oxygen meter project. He began by explaining
that oxygen demonstrates strong paramagnetic properties. This paramagnetism allows oxygen atoms to be attracted to outside
magnetic fields, a tendency not exhibited by other gases in our atmosphere. By measuring the magnetic attraction of a sample
of mixed gases, one would be able to determine the percentage of oxygen present. He believed that a torsion balance, a sensitive
device used to measure weak forces, could determine the magnetic force exerted by oxygen in mixed gases. In addition to outlining
the design principles behind his apparatus, Pauling requested salary allocations for two of his best researchers - Reuben Wood and Sidney Weinbaum.