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I have measured the oxygen level in my continuous furnace, and it's low, but my parts still come out oxidized. Why?

Don Bowe Don Bowe
Sr. Applications Engineer
Guido Plicht
Senior Research Engineer

This is a question that comes up frequently. When troubleshooting for oxidation in a continuous furnace atmosphere, it's important to measure both oxygen level and dew point. Here's why.

The dew point is a measure of the moisture content of a gas and is the temperature at which water vapor in a sample gas starts to condense. Oxygen concentration is simply that—a measure of the partial pressure of oxygen.

When a gas sample is extracted from the hot zone of a furnace for analysis, reactive gases like H2, CO, or CxHy have already combined with any O2 present to produce moisture and other gaseous components. As a result, depending on the furnace temperature and how the sample is obtained, your analyzer will often display a low oxygen level. In most applications, a low oxygen level and a low dew point are required to control the process and prevent oxidation.

Click here to find the Gas Atmosphere Analysis Guidelines

For further details contact Shawn Lainchbury tel: +44 (0) 1932 249 398.
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