Cooling Water System Turbidity Measurement
THE IMPORTANCE OF TURBIDITY CONTROL IN COOLING WATER
Cooling water systems are constantly exposed to suspended solids — from corrosion, environmental debris, biological activity, and process contamination. If left unchecked, these particles drive fouling, scale formation, reduced heat transfer efficiency, and unplanned maintenance.
Turbidity is the most practical early warning indicator of changing water quality. Optical turbidity analyzers provide continuous, real-time indication of water cleanliness and purity. Contamination originates from a variety of sources within and around cooling water systems, and left unchecked, can create significant issues with line components like heat exchangers, valves and pumps. Typical sources include:
- Corrosion: rust, scale, and iron oxides from piping and equipment.
- Environmental: dust, pollen, airborne debris entering open towers.
- Biological: algae, slime, and biofilm fragments • Process Leaks: contamination through heat exchanger failures.
- Chemical Residues: overdosing of coagulants or dispersants
WHY OPTICAL SYSTEMS ARE SUPERIOR
Even a small rise in turbidity can signal accelerating fouling—well before visible problems or operational inefficiencies appear. The benefits provided by monitoring turbidity are numerous:
- No consumables or reagents – lower lifecycle cost
- True real-time measurement – faster response than grab sampling
- High chemical resistance – compatible with cooling water treatment chemicals
- Reduced maintenance – less fouling, easier cleaning
- Stable long-term performance – minimizes recalibration
TYPICAL TURBIDITY RANGES AND CONTROL LIMITS IN
COOLING WATER SYSTEMS
Even a small rise in turbidity can signal accelerating fouling—well before visible problems or operational inefficiencies appear. The benefits provided by monitoring turbidity are numerous:
- Early detection of fouling and scaling
- Improved chemical treatment efficiency through better dosing control
- Reduced manual sampling and lab testing frequency
- Increased equipment life and efficiency for heat exchangers, pumps, valves, and piping
- Support for environmental discharge compliance
The Exner EXPure 191 is a high-precision optical turbidity sensor designed for accurate, continuous monitoring in industrial water systems. For cooling water, it’s ideal in locations where measurement accuracy, low biofouling, and stable long-term performance are critical.
| System Type | Normal Operating Range | Action Level (Alarm) |
|---|---|---|
| Closed Loop | < 1 NTU | > 2 NTU |
| Open Recirculating Tower | 1 – 5 NTU | > 10 NTU |
| Once-Through Cooling | < 2 NTU | > 5 NTU |
- High-precision optical measurement using scattered light detection
- Compact, construction with excellent chemical resistance
- Factory-calibrated and field-verifiable for long-term accuracy
- Simple side stream tube connection
- Optional bubble eliminator
Ideal for installations requiring higher measurement precision or where cleanliness and low biofouling are priorities, such as food, beverage, or pharmaceutical cooling systems.
OPTICAL TURBIDITY INSTRUMENTS PROVIDE ROBUST, LOW-MAINTENANCE SOLUTIONS
The Kemtrak TC007 is particularly well-suited for cooling water monitoring in places where reliability, low maintenance, and rugged performance matter. Its fiber-optic design and robust measurement principle make it ideal for dirty, chemically treated, or harsh process environments. A wide range of flow through measurement cells make it adaptable to different line sizes and connection types.
- True in-line optical measurement using dual-beam backscatter technology
- High chemical and temperature resistance for harsh industrial environments
- No moving parts, no glass windows to foul — ideal for dirty water applications
- SMA 905 fiber optic connectivity allows remote sensor mounting for safety and convenience
- Low maintenance and fast response time, well suited for automated control loops
The TC007 is ideal for continuous monitoring on cooling tower return lines, bypass loops, and discharge points
SOUTH FORK INSTRUMENTS
3845 Buffalo Road
Auburn, CA 95602
Tel: (+1) 925-461-5059
