How to Monitor Water Purity with Resistivity Meters
Ultimate Guide to Water Conductivity & Resistivity Meters (2025 Edition)
Conductivity & TDS Relationship Explained
✔ Direct Correlation: Conductivity increases with dissolved solids concentration
✔ Key Conversion Rates:
• 1.4μS/cm ≈ 1 ppm (as CaCO₃)
• 1μS/cm ≈ 0.5 ppm water hardness
✔ Measurement Tools:
• Conductivity meters
• TDS analyzers
Pro Tip: For pure water systems, resistivity (MΩ·cm) is the preferred measurement unit
Industrial Conductivity Meter Features
Smart Temperature Compensation
• Auto-adjusts readings to 25°C standard
• Wide operating range: 5-50°C
Rugged Sensor Design
• 316L stainless steel construction
• IP65 protection rating
• 1/2" NPT threaded connection
Advanced Electronics
• 2% FS accuracy
• ±2% long-term stability
• Dual-shielded coaxial cable
RM-220 vs CM-230 Comparison
| Parameter | RM-220 (Resistivity) | CM-230 (Conductivity) |
|---|---|---|
| Measurement Range | 0-18.2 MΩ·cm | 0-2000 μS/cm |
| Electrode Constant | 0.05 cm⁻¹ | 1.0 cm⁻¹ |
| Accuracy | ≤1.5% FS | ≤1.5% FS |
| Output Signal | 4-20mA | 4-20mA |
5 Key Applications
1. Reverse Osmosis Monitoring
• Track membrane performance
• Detect integrity breaches
2. EDI Systems
• Verify ultra-pure water quality
• 18.2 MΩ·cm measurement
3. Boiler Feedwater
• Prevent scale formation
• Optimize chemical dosing
4. Pharmaceutical Water
• USP/EP compliance
• Critical process control
5. Wastewater Treatment
• TDS discharge monitoring
• Process optimization
Installation & Maintenance
Mounting Guidelines
✔ Panel-mount design (45×91mm cutout)
✔ Keep 10cm clearance for ventilation
✔ Avoid strong electromagnetic fields
Calibration Schedule
• Monthly: Verify with standard solutions
• Quarterly: Electrode cleaning
• Annually: Full system check
Warning: Never use abrasive cleaners on sensors
Troubleshooting Guide
| Issue | Possible Cause | Solution |
|---|---|---|
| Erratic Readings | Cable interference | Use shielded cable |
| No Display | Power supply issue | Check 220V AC input |
| Slow Response | Fouled electrode | Clean with mild acid |
| High Error | Wrong cell constant | Reconfigure settings |
Why Choose Our Meters?
✔ NSF-compliant materials
✔ 24/7 continuous monitoring capable
✔ Easy integration with PLC/SCADA
✔ warranty included
Industry Fact: Proper conductivity monitoring can reduce maintenance costs by 30%
