It performs detection through two cuvette windows made of fused quartz. When these windows become contaminated, the instrument cannot distinguish whether the reduction in UV radiation intensity is caused by the ozone in the cuvette or by the contaminated cuvette windows. Therefore, an important principle for operating an ozone photometer is: "The only real enemy of an ozone light cell is contaminants!"

When measuring ozone, especially in industrial environments, taking comprehensive protective measures to prevent contaminants that may be present in the ozone sample gas from entering the ozone analyzer will yield significant results.

For this reason, gaseous ozone analyzers need to be equipped with dust filters. The filters should be checked regularly for contaminants, and replaced every 3 months depending on the particle content in the sample gas.

The ozone gas generated by most types of ozone generators contains more or less nitrogen oxides. This is because nitrogen is mixed into the feed oxygen either intentionally or unintentionally. Among them, medium and large-sized ozone generators are usually operated under conditions of high nitrogen doping. If the connection between the ozone analyzer and such generators is not disconnected during maintenance of the generators, the risk of contaminants entering the analyzer will be particularly high.