Overview
The QIWEI QW-COD-B Portable COD Rapid Measurement Instrument is an instrument for the measurement of chemical oxygen demand (COD) in water. The chemical oxygen demand is a key indicator of the degree of pollution of organic matter in water. The instrument uses a special Reagent and a rapid catalytic method (chromium method), which can quickly and accurately obtain COD values through digestion and spectrophotometry. It is suitable for the monitoring of a variety of industrial wastewater and domestic wastewater.
Features
1. Adopt special composite catalyst Reagent, which has the ability to accelerate reaction and resist chloride ion interference.
2. Measurement range is wide, covering 0~ 150mg/L low range and 100~ 1000mg/L high range, high concentration water samples can be diluted.
3. The digestion temperature is precisely controlled and the temperature field is uniform.
4. High measurement efficiency, multiple water samples can be measured simultaneously within 30 minutes (9, 12, or 25 depending on the configuration).
5. Stability and accuracy of the instrument, strong practicability, to meet different user requests.
6. Data storage function, can record 20 measurement results.
Principle
The instrument uses a rapid catalytic method (chromium method). The water sample and a specific Reagent containing a composite catalyst undergo a rapid oxidation and reduction reaction in Digester. After the reaction, trivalent chromium ions are generated. The instrument measures the concentration of trivalent chromium ions by Spectrophotometric method, spectrophotometry, and calculates the corresponding chemical oxygen demand (COD) value of the water sample.
Applications
Chemical, petroleum, coking, papermaking, metallurgy, brewing and other industrial wastewater, urban sewage, domestic sewage, surface water in rivers and lakes basins
Steps
Prepare water samples, high concentrations (> 1000mg/L) need to be diluted in advance.
2. Add a special Reagent to the water sample.
3. Place the sample in Digester and digest at 165 +/- 1 ° C for 15 minutes.
4. After the digestion is completed, let it chill down.
5. Use the instrument for spectrophotometric determination to read or record COD values.
Notice
• Measurement error: in the range of 5 to 100 mg/L, the absolute error is ≤ +/- 5 mg/L; in the range of 100 mg/L to 1000 mg/L, the relative error ≤ +/- 5%.
The digestion temperature should be strictly controlled to 165 +/- 1 ° C.
• Ambient Temperature of the instrument is 5~ 40 ℃, relative humidity should be < 85% and no condensation.
• Power Supply is AC220V +/- 10%/50Hz.
• Depending on the instrument configuration, the number of water samples that can be measured at a single time may be 9, 12 or 25.
• Before use, make sure that the instrument is calibrated accurately and in accordance with the operating specifications.
