>>Application
This method is applicable to wastewater with total nitrogen concentrations within the range of 0-300 mg/L.
>>Technical parameters
1. Measurement Method: Potassium persulfate oxidation UV spectrophotometry
2. Measurement Range: 0-300 mg/L
3. Accuracy: ≤±10%
4. Repeatability: ≤±5%
5. Measurement Cycle: Minimum cycle is 45 minutes; color development time can be adjusted flexibly between 5-30 min based on environmental conditions.
6. Sampling Cycle: Adjustable time interval (10-9999 min) or on-the-hour measurement mode.
7. Calibration Cycle: Adjustable at any interval from 1-99 days.
8. Maintenance Cycle: ≥168 hours, with each maintenance lasting ~1 hour.
9. Reagent Consumption: <0.50 CNY per sample.
10. Outputs: RS-232, 4mA-20mA, RS-485.
11. Environmental Requirements: Temperature-controlled indoor environment (recommended: 5-40°C); humidity 45%-85%.
12. Power Supply: AC 220±10% V, 50±1% Hz, 5A.
13. Dimensions: Height 1500 × Width 500 × Depth 450 mm.
14. Additional Features:
- Data retention during abnormal alarms or power outages.
- Touchscreen display and command input.
- Automatic discharge of residual reactants and resumption of operation after power restoration or system reset.
>>Feature
Unique Design: This product features a distinctive design that ensures lower failure rates, reduced maintenance requirements, minimal reagent consumption, and higher cost-effectiveness compared to similar products.
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Selector Valve Assembly:
- Enables flexible reagent sampling timing and diverse channel configurations.
- Minimizes dead volume for easy maintenance and extended service life.
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Micro-Dosing Unit:
- Utilizes a visual photoelectric system for precise reagent measurement, eliminating quantitative errors caused by peristaltic pump tube wear.
- Achieves accurate micro-dosing with 0.7 mL per dose, significantly reducing reagent usage.
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Sample Introduction Unit:
- Employs a peristaltic pump with negative pressure suction, creating an air buffer zone between reagents and the pump tube to prevent corrosion.
- Simplifies and enhances flexibility in reagent mixing.
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Sealed Digestion Unit:
- Operates under high-temperature and high-pressure conditions to accelerate reactions.
- Eliminates corrosion risks from volatile gases in open systems.
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Reagent Tubing:
- Uses imported modified PTFE (polytetrafluoroethylene) transparent tubing with an inner diameter >1.5 mm to minimize clogging by particulate matter in water samples.
>>Analytical Principle
Under alkaline medium conditions at 120-125°C, using potassium persulfate as an oxidizing agent, not only are ammonia nitrogen and nitrite nitrogen in the water sample oxidized to nitrate, but most organic nitrogen compounds in the sample are also converted to nitrate. The absorbance is measured at wavelengths of 220 nm and 275 nm using ultraviolet spectrophotometry. The nitrate nitrogen absorbance value is calculated using the formula A = A 220− 2A 275, thereby determining the total nitrogen content.
