Chlorine Dioxide (ClO2) Sensor Calibration: Best Practices

Chlorine dioxide (ClO2) is widely used as a disinfectant and bleaching agent in water treatment, pulp and paper, and food processing — and because it's typically generated on-site rather than stored, reliable detection matters both for worker safety and for process control.

Why ClO2 calibration has its own quirks

ClO2 sensors can be cross-sensitive to chlorine (Cl2), meaning a poorly calibrated or drifting sensor may misread one gas as the other. ClO2 itself is also less stable than many calibration gases, which historically made cylinder-based ClO2 calibration gas inconsistent close to a cylinder's rated shelf life. On-demand generation, produced fresh at the point of use, avoids that aging problem entirely.

Calibration tips

• Calibrate at a concentration close to your actual alarm threshold, and confirm the sensor isn't cross-triggering on chlorine if both gases are monitored in the same area.
• Because ClO2 is typically generated on-site, coordinate calibration timing with your water treatment process schedule to avoid disrupting disinfection monitoring.
• Document every calibration — ClO2 monitoring is frequently tied to both worker safety compliance and water treatment process records, so a clean log serves double duty.

ACD's ClO2 source is available in multiple capacities to match your calibration volume. Shop ClO2 calibration gas.