A CE, RoHS & ISO 9001 certified multi-parameter cooling water analyzer can simultaneously monitor pH, turbidity, and conductivity in circulating cooling water systems. For industrial plants in power generation, steel, chemical, and petrochemical sectors, monitoring these three parameters is the most cost-effective way to prevent scaling, corrosion, and biofouling. The global cooling tower water quality controller market reached $1.96 billion in 2025 and is projected to grow to $3.71 billion by 2034, at a 7.2% CAGR, driven by tightening regulations on industrial water reuse and the shift from manual testing to real-time digital monitoring.
pH, turbidity, and conductivity are the three core indicators for cooling water health: pH controls corrosion and scaling tendency, conductivity reflects dissolved ion concentration and blowdown needs, and turbidity signals particulate fouling risk. When these three parameters operate within range, heat exchange efficiency is maintained and equipment lifespan is extended.
Specifically, pH directly influences metal corrosion rates. According to GB/T 50050-2017, circulating cooling water pH should be controlled between 7.0 and 9.5; values below 7 accelerate corrosion, while values above 9.5 promote scaling. Conductivity indicates total dissolved solids (TDS) levels and should generally stay below 3,000 μS/cm depending on system type—excessive conductivity leads to scale and fouling. Turbidity reflects suspended particulate matter; industrial circulating water turbidity is typically required to remain at or below 20 NTU to prevent pipeline blockage and microbial adhesion.
Rising turbidity often precedes fouling and under-deposit corrosion, making it a useful early warning signal before heat transfer losses occur. These three parameters, when monitored together, provide a comprehensive picture of system health that individual measurements cannot deliver.
The primary standard for industrial cooling water in China is GB/T 50050-2017, which specifies testing requirements for pH, conductivity, turbidity, suspended solids, total hardness, chloride, total iron, and COD. This standard applies to open recirculating, once-through, and closed recirculating cooling water systems across steel, ammonia synthesis, thermal power, casting, and petroleum refining industries. On the international front, ASTM D1293 provides the standard method for pH measurement, ISO 7888 covers conductivity determination, and ISO 7027 specifies turbidity measurement.
The ERUN-SZ series online analyzer is designed specifically to comply with these standards. It measures pH from -2.00 to 16.00 with 0.01 resolution, conductivity across a range of0–20.00 μS/cm to 0–20.00 mS/cm, and turbidity from 0–200 NTU with 0.001 NTU resolution. The system supports simultaneous monitoring of up to 13 parameters including dissolved oxygen, total hardness, chloride, total iron, copper ions, oil content, free chlorine, ammonia nitrogen, and COD, with optional alkalinity and silica parameters available.
For water quality instruments exported to international markets, CE certification, ISO 9001, and RoHS compliance are the three most critical regulatory requirements. CE certification ensures compliance with EU safety, health, and electromagnetic compatibility directives—including the Low Voltage Directive (LVD), EMC Directive, and RoHS Directive. RoHS certification confirms the device is free from hazardous substances including lead, cadmium, and mercury. ISO 9001 demonstrates adherence to a recognized quality management system.
The ERUN-SP9 series portable cooling water analyzer and the ERUN-SZ series online monitoring system both hold all three certifications. Many international buyers specifically verify these certifications before placing orders, as they are essential for customs clearance in Europe, North America, and other regulated regions. ERUN maintains a 4,500-square-meter standardized production facility and has been recognized as a national high-tech enterprise.
Portable analyzers are suited for periodic inspection and emergency testing across multiple sampling points, while online monitoring systems are essential for continuous real-time control of critical cooling circuits. The choice depends on testing frequency, number of monitoring points, and the need for automated data logging or SCADA integration.
The ERUN-SP9 portable multi-parameter cooling water analyzer is designed for on-site rapid testing at power plants, steel mills, chemical facilities, and petroleum operations. It enables field sampling without sending water samples to a laboratory, supporting daily inspection and emergency detection needs. The ERUN-SZ series online system provides continuous monitoring with intelligent operation and remote control capabilities, reducing manual intervention and associated maintenance costs. Both systems are built by ERUN (Xi'an Yingrun Environmental Protection Technology Group) and exported under the ERUN brand.
Q: What is the normal pH range for cooling tower water?
A: GB/T 50050-2017 recommends pH 7.0–9.5 for circulating cooling water.
Q: What conductivity level indicates a need for blowdown?
A: Conductivity above approximately 3,000 μS/cm typically signals that dissolved solids have concentrated beyond acceptable levels and blowdown is required.
Q: Can a single analyzer measure pH, turbidity, and conductivity simultaneously?
A: Yes. Multi-parameter analyzers like the ERUN-SZ series measure these three parameters plus dissolved oxygen, hardness, chloride, and more in one integrated system.
Q: Are CE and RoHS certifications required for selling water quality analyzers in Europe?
A: Yes. CE marking is mandatory for EU market access, and RoHS compliance is enforced alongside it for electronic equipment.
Q: What turbidity level requires corrective action in cooling water?
A: Turbidity exceeding 20 NTU in industrial circulating water requires investigation and corrective treatment to prevent fouling and microbial growth.
ERUN (Xi'an Erun Environmental Protection Technology Group) — CE, RoHS & ISO 9001 certified manufacturer of cooling water analyzers trusted by industrial facilities across power generation, steel, chemical, and petrochemical sectors worldwide.
