Water Quality Probe Comparison
Fourteen single-parameter probes share the same RS485/Modbus interface and can run on one data logger. Compare measuring principle, range, accuracy and housing material to plan a multi-probe monitoring station.
| ZWQ-CND1 | ZWQ-PH1 | ZWQ-TUB1 | ZWQ-COD1 | ZWQ-INH1 | ZWQ-TP1 | ZWQ-ORP1 | ZWQ-IF1 | ZWQ-ICL | ZWQ-CHL1 | ZWQ-CT1 | ZWQ-BGA1 | ZWQ-DO1 | ZWQ-INO | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Measuring principle | Quadrupole graphite electrode | Glass electrode | Optical scattering | Ultraviolet absorption (double-beam) | Ion electrode | Near infrared absorption spectrometry | Glass electrode | Ion electrode | Ion electrode | Fluorescence (optical) | Clark current | Fluorescence | Fluorescence | Ion-selective electrode (polymer membrane) |
| Measurement range | 0-200,000 μS/cm | 0-14 pH | 0-1000 NTU | 0-500 mg/L | 0-1000 mg/L | 2-1000 cm | -2000 to 2000 mV | 0-1000 mg/L | 0-10,000 mg/L | 0-500 µg | 0-2 mg/L | 0-2000 Kcells/mL | 0-20 mg/L | — |
| Accuracy | ±1% | ±0.1 pH | ±5% | ±7% | 10% or 0.1 mg/L | ±5% | ±1 mV | ±5% | ±10% | ±5% | ±1% | ±5% | ±0.1 mg/L | — |
| Self-cleaning function | — | — | Yes | Yes | — | Yes | — | — | — | Yes, removable brush | — | Yes, brush | — | — |
| Built-in temperature compensation | — | PT1000 | — | — | PT1000 | — | — | — | PT1000 | — | — | — | — | — |
| Housing material | POM | POM | Titanium alloy | 316L stainless steel | POM | 316L stainless steel | POM | POM | POM | 316L stainless steel | CPVC | 316L stainless steel | POM | — |
| Interface | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) | RS485 (Modbus RTU) |
Frequently asked questions
Do all these water quality probes share the same interface? +
Yes. Every probe in this range outputs RS485 with Modbus RTU protocol, so they can share a single data logger or telemetry system regardless of which parameters you deploy.
Which probes need periodic calibration and which don't? +
The dissolved oxygen sensor (ZWQ-DO1) needs no initial calibration and no electrolyte. Most electrode-based probes (pH, ORP, conductivity, ion-selective) need periodic calibration against reference solutions, standard practice for this sensor type.
Why do some probes have a self-cleaning function and others don't? +
Self-cleaning brushes are fitted to optical sensors most prone to biofouling in surface water: turbidity, COD, transparency, chlorophyll and blue-green algae. Electrode-based probes (pH, conductivity, ORP, ion-selective sensors) don't need mechanical cleaning in the same way.