Different monitoring applications require different parameters. Water quality monitoring focuses on organic pollution, nutrients, physical indicators and selected toxic substances. Flue gas monitoring focuses on gas components, particulate matter and operating conditions. VOC and toxic gas monitoring depends on target compounds and safety requirements.
Water Parameters
Huisheng separates water indicators into wet-chemical analyzer indicators, sensor indicators and laboratory verification indicators. Sample condition and range are essential.
Water quality parameters can be divided into organic pollution indicators, nutrient indicators, physical sensor indicators and project-specific toxic indicators. This distinction matters because different indicators may require different measurement principles, sample handling and maintenance planning.
For example, COD, NH3-N, TP and TN are often discussed as analyzer-based parameters, while pH, DO, turbidity, conductivity and temperature are commonly sensor-based. Heavy metals, cyanide, fluoride ion (F-) or volatile phenol may need more specific confirmation of method, detection limit and range.
| Parameter | Typical Medium | Purpose |
|---|---|---|
| COD | Wastewater / industrial effluent | Organic pollution monitoring |
| BOD | Wastewater | Biodegradable organic matter evaluation |
| NH3-N | Wastewater / surface water | Nitrogen pollution control |
| TP | Wastewater / surface water | Phosphorus and nutrient control |
| TN | Wastewater / surface water | Total nitrogen monitoring |
| Heavy metals | Industrial wastewater | Metal pollution monitoring |
| Cyanide | Industrial wastewater | Toxic substance monitoring |
| Fluoride Ion (F-) | Industrial wastewater / water source | Specific ion monitoring |
| Volatile phenol | Industrial wastewater | Organic toxic indicator |
| pH | Water | Acidity and alkalinity |
| DO | Surface water / process water | Oxygen condition |
| Turbidity | Water | Suspended particle indication |
| Conductivity | Water | Ionic concentration indication |
| Temperature | Water | Basic water condition |
Gas Parameters
Gas indicators Huisheng reviews with stack temperature, pressure, humidity, dust load, sampling distance and reporting requirements.
Flue gas and emission parameters Huisheng reviews with the stack condition. SO2, NOx, CO, CO2, O2, HCl and HF are gas components, while dust, flow, pressure, temperature and humidity describe emission condition and calculation context.
If a project involves high moisture, corrosive gas or heavy dust, sampling and pretreatment may become as important as the gas analyzer itself. Huisheng therefore reviews both concentration indicators and operating condition indicators in the final parameter list.
| Parameter | Typical Medium | Purpose |
|---|---|---|
| SO2 | Stack gas | Sulfur emission monitoring |
| NOx | Stack gas | Nitrogen oxide monitoring |
| CO | Combustion gas | Combustion and safety indicator |
| CO2 | Stack gas | Combustion and process monitoring |
| O2 | Stack gas | Oxygen correction and combustion reference |
| HCl | Waste incineration / chemical exhaust | Acid gas monitoring |
| HF | Industrial exhaust | Acid gas monitoring |
| Dust / PM | Stack gas | Particulate emission monitoring |
| Flow | Stack gas | Emission calculation support |
| Pressure | Stack gas | Operating condition |
| Temperature | Stack gas | Operating condition |
| Humidity | Stack gas | Moisture correction |
VOC and Toxic Gas
VOC and toxic gas monitoring depends on target compound, method, hazardous area requirement, concentration range and sampling path.
Huisheng begins VOC and toxic gas projects with target compound confirmation. Total VOCs, NMHC, benzene series, H2S, NH3, CO, O2 and combustible gases can require different detection principles, calibration gases and installation approaches.
The monitoring purpose also matters. A boundary point, workshop alarm point, source emission point and emergency detection task may use different instrument types even when the gas name looks similar.
| Parameter | Typical Medium | Purpose |
|---|---|---|
| VOCs | Industrial exhaust / ambient air | Organic compound monitoring |
| NMHC | Industrial emission | Non-methane hydrocarbon monitoring |
| Benzene series | Chemical / coating / petrochemical | Specific organic compound monitoring |
| H2S | Wastewater / chemical / oil and gas | Toxic gas warning |
| NH3 | Chemical / wastewater / refrigeration | Toxic gas detection |
| CO | Combustion / enclosed spaces | Safety monitoring |
| O2 | Confined space / process gas | Oxygen level monitoring |
| Combustible gases | Industrial sites | Explosion risk warning |