Oxygen analyzers play an important role in the safe production of pharmaceuticals. Using powders and solvents in large quantities leads to significant risk of explosions. Removing oxygen via a blanket gas, typically nitrogen, reduces the chance of a fire or an explosion.

Pharmaceuticals and Specialty Chemicals are typically produced in batches by mixing several components in a reactor. These reactors vary in size from table top glass jars to large stainless steel or glass lined vessels with a mixer (like a giant household food blender). The vessel will be subjected to nitrogen blanketing prior to and during batch production. The oxygen levels need to be monitored at all times for plant and operator safety. In the past, companies used to just permanently supply N2 to the process and not worry about the oxygen level. However, N2 is a consumable with an associated cost that can and should be limited. This is achieved by monitoring the oxygen level and shutting the N2 supply when the O2 levels are safe.

Inertisation in centrifuges.
In pharmaceutical production processes organic solvents are frequently used. To be able to control the resulting vapor mixtures, which pose an explosion risk, scraper centrifuges will be purged with nitrogen prior to startup. As a result, the centrifuge remains in a nitrogen atmosphere during production. To compensate for air ingress via leaks, oxygen analyzers are used to control the N2 injection.
If the inertisation is done with pressure the oxygen content of the exhaust airstream is determined with a portable measuring device such as the GPR-1200 series on the initial start-up of the inertisation.
For an installation with installed online oxygen measurement, the O2 content of the exhaust airstream is constantly measured, and in the event of excess oxygen of e.g. 6%, nitrogen is added until the oxygen content has been reduced back to 4% to meet the LEL of the process.