pH Sensor Redundancy

Definition

The operational safeguard of installing a backup pH probe so that a silent failure of the primary sensor does not leave acid feed uncontrolled.

In the author’s case the primary pH sensor failed silently and the customer had declined the suggested redundant probe, so acid stopped feeding without any alarm. Weeks passed before the problem was discovered, by which time the entire cooling tower had scaled. The episode shows that instrumentation reliability, not just chemistry, controls whether the carbonate equilibrium stays where it is supposed to.

Related concepts

Acid Feed for Scale Control · Calcium Carbonate Scaling

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Part of The Blueprint of Water · 🛠️ operations