What Five-Parameter Automatic Monitors Measure ？

Water quality directly impacts human health, ecological balance, and industrial processes. At the heart of modern aquatic monitoring lies the five-parameter automatic monitor—a sophisticated system designed to track the fundamental indicators of water health in real time.

These devices simultaneously measure pH, temperature, dissolved oxygen (DO), conductivity, and turbidity, forming the cornerstone of environmental compliance, drinking water safety, and industrial process control worldwide.

 Core Parameters Measured: The Science Behind Each Indicator

1、pH

Measurement Principle: Glass electrode method, where a potentiometric difference arises between the sensing electrode and reference electrode based on hydrogen ion activity.

Range and Precision: 0.00–14.00 pH, with high accuracy (±0.01 pH) and automatic temperature compensation (0–50°C).

Significance: Critical for assessing water corrosivity, nutrient bioavailability, and ecosystem stability. Acidic or alkaline shifts can indicate industrial pollution or algal blooms.

2、Dissolved Oxygen (DO)

Measurement Principle: Membrane electrode (amperometric) or optical fluorescence (luminescence) methods. Optical sensors use fluorescent dyes whose quenching by oxygen correlates with DO concentration.

Range and Precision: 0.00–20.00 mg/L, with ±0.1 mg/L accuracy. Includes PT100 temperature compensation.

Significance: Low DO levels threaten aquatic life and indicate organic pollution (e.g., sewage), while supersaturation may suggest algal overgrowth.

3、Conductivity

Measurement Principle: Four-electrode or electromagnetic induction methods. Electrodes measure current flow between poles, proportional to ion concentration.

Range and Precision: 10 μS/cm to 500 mS/cm, with nonlinear temperature compensation for natural waters.

Significance: Reflects total dissolved solids (TDS), salinity, and inorganic pollution (e.g., nitrates, heavy metals).

4、Turbidity

Measurement Principle: 90° scattered light nephelometry (per ISO 7027). Infrared light (860 nm) eliminates color interference.

Range and Precision: 0–4,000 NTU/FNU, ±3% accuracy. Sapphire lenses resist scratching.

Significance: High turbidity signals erosion, algal blooms, or sewage ingress, affecting disinfection efficiency and light penetration.

5、Temperature

Measurement Principle: PT100 platinum resistance thermometers or thermistors.

Range and Precision: −5°C to 60°C, ±0.5°C accuracy.

Significance: Affects DO saturation, chemical reaction rates, and biological activity. Used to compensate other sensor readings.

Applications: From Source to Sea

These monitors deploy across diverse aqueous environments:

Drinking Water & Wastewater: Ensure pH/DO compliance in treatment plants; monitor effluent turbidity at discharge points.

Surface Water: Profile rivers/lakes for conductivity spikes (indicating runoff pollution) or DO crashes (eutrophication).

Industrial Processes: Control cooling water conductivity (scaling prevention) and boiler pH (corrosion control).

Aquaculture: Maintain DO >5 mg/L for fish health; track temperature-triggered disease outbreaks.