Why dissolved oxygen measurement is critical to quality

Oxygen (O₂) is the primary enemy of beverage quality and a major contributor to industrial equipment degradation. Precise measurement of Dissolved Oxygen (DO) is non-negotiable for quality control.

Beverage quality and shelf-life

In brewing, soft drinks, and juice production, DO must be kept to absolute minimums, often below 10 ppb.

• Oxidation and staling: O₂ catalyses chemical reactions that produce undesirable compounds, leading to "stale" or "cardboard" flavours. The total package oxygen (TPO) value is often the sum of DO and headspace oxygen.
• Color and clarity: Excessive DO can cause unwanted browning and haze formation, impacting the visual appeal of the product.
• Cold chain integrity: Even small amounts of O₂ can significantly reduce shelf-life, especially when temperature fluctuations occur.

Industrial corrosion prevention

In boiler feedwater and cooling systems, DO is a powerful corrosive agent.

The presence of dissolved oxygen accelerates the electrochemical reaction that leads to pitting and failure of ferrous metals, represented by the simplified reaction:

$$ 2\text{Fe} + \frac{3}{2}\text{O}_2 + n\text{H}_2\text{O} \to \text{Fe}_2\text{O}_3 \cdot n\text{H}_2\text{O} \text{ (Rust)} $$

• Boiler efficiency: DO removal (deaeration) is essential to maintain high efficiency and prevent system leaks.
• Chemical dosing: Accurate DO monitoring allows for precise control of oxygen scavenger chemicals, minimizing usage and cost while ensuring protection.