White Paper: Optical Oxygen Measurement Improves Ease Of Use And Reliability

Amperometric oxygen measurement systems offer reliable and easy to use solutions for many applications. But the interest of the market for optical solutions increases since optical technology offers significant advantages in demanding applications like fermentation in biotech and brewery processes. The optical technology shows significant advantages towards amperometric measurement which need to be fully understood in order to maximize the benefits of chemo-optical measurement techniques.

Fluorescence, a natural phenomenon
Optical sensors for dissolved oxygen (DO) measurement use the principle of fluorescence quenching for oxygen measurement. This technology was first published in 1931 but it took nearly 80 years to be suitable for process analytical sensors. Optical oxygen measurement with fluorescence is in contrast to absorption not a direct oxygen measurement. With fluorescence the interaction of oxygen with another substance is measured. Some molecules which are able to absorb light of a specific wavelength can release the absorbed energy after a short delay time as light. This mechanism is called Luminescence. Fluorescence is a special form of luminescence where the lifetime of light has different properties. Luminescence is present in many situations. Illumination of watches, security features for bank notes, are a few examples of daily life.

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