OZ1.2MA2 Sensor in Ozone Concentration Monitoring and Control for Mineral Water Production

OZ1.2 Ozone Sensor made in Germany

Stable Ozone Monitoring in Mineral Water Production

A mineral water plant uses an ultrafiltration (UF) + reverse osmosis (RO) process with ozone disinfection.
The system integrates a German-made OZ1.2MA2 ozone sensor for real-time ozone monitoring and control.

Key Challenge

During commissioning, ozone concentration could not remain stable:

Increased to 0.5 ppm, then dropped below 0.1 ppm within 10 minutes
Calibration could not be completed due to unstable conditions
Both sensor output and lab titration showed the same trend → not a sensor issue
Root Cause

The issue was traced to water chemistry, not the sensor:

High alkalinity in ultrafiltration water (180 mg/L as CaCO₃)
Initial UF:RO ratio = 8:2, causing excessive alkalinity
Ozone reacted rapidly with bicarbonates → accelerated ozone consumption

After adjusting the ratio to 2:8:

Alkalinity reduced to ~52 mg/L
Ozone stabilized at 0.5 ppm for over 30 minutes
Solution
1. Process Optimization
UF:RO ratio fixed at 2:8
Alkalinity controlled at 50–60 mg/L
Flow rate optimized to 20–25 L/h for stable sensor response
2. Closed-Loop Control

Using the sensor’s 4–20 mA output:

<0.1 ppm → start ozone generator
>0.25 ppm → stop ozone generator

→ Ensures effective disinfection without overdosing

3. Calibration & Maintenance
Calibration performed under stable conditions (0.25 ppm standard)
Measurement accuracy maintained within ±2%
Routine maintenance:
Membrane cap: every 6 months
Electrolyte: every 3 months
Results
Stable ozone concentration control achieved
Reliable calibration and long-term operation
No unnecessary sensor replacement required
Key Takeaways
Sensor performance was not the issue — process design was
High alkalinity can significantly increase ozone consumption
Proper UF/RO ratio + real-time monitoring is critical

With its:

Wide measuring range (0.005–2.000 ppm)
High resolution (0.001 ppm)
Stable 4–20 mA output
Wide pH compatibility (2–11)

the OZ1.2 ozone sensor provides a reliable solution for low-concentration ozone monitoring in mineral water production.