Overview
The Benchtop COD Rapid Analyzer (Model QW-COD-T) is an instrument for the determination of chemical oxygen demand (COD) in water. COD is a key indicator of the degree of organic matter pollution in water. The instrument uses a special Reagent and a rapid catalytic method (chromium method) to quickly and accurately analyze the COD value of water samples through digestion and spectrophotometry, and is suitable for a variety of water quality monitoring scenarios.
Features
1. Adopt special composite catalyst Reagent to accelerate the reaction and resist chloride ion interference.
2. Measurement range is wide, supporting 0~ 150mg/L low range and 100~ 1000mg/L high range (> 1000mg/L can be diluted).
3. The measurement error is small, the absolute error in the low concentration range is ≤ +/- 5 mg/L, and the relative error in the high concentration range ≤ +/- 5%.
4. The digestion temperature is precisely controlled at 165 +/- 1 ° C, and the digestion time is 15 minutes.
5. High measurement efficiency, 9, 12 or 25 water samples can be measured simultaneously in 30 minutes (depending on the configuration).
6. High temperature control accuracy, temperature Indication Error ＜ +/- 1 ℃, temperature field uniformity ≤ 2 ℃.
7. With Data storage function, it can store 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 rapid oxidation and reduction reaction in Digester at 165 +/- 1 ° C. After the reaction, trivalent chromium ions are generated, and their concentration is related to the COD value of the water sample. Subsequently, the concentration of trivalent chromium ions is determined by Spectrophotometric method, spectrophotometry, and the corresponding COD value is calculated.
Applications
Chemical, petroleum, coking, papermaking, metallurgy, brewing and other industrial wastewater, urban sewage, domestic sewage, surface water in rivers and lakes basins
Standards
Measuring method conforms to the fast catalytic method (chromium method)
Steps
1. Prepare Water Samples and Special Reagents.
2. Add the water sample and Reagent to the digestion tube.
3. Place digestion tubes in Digester and digest at 165 +/- 1 ° C for 15 minutes.
4. After the digestion is complete, remove and chill down.
5. Use the instrument for spectrophotometric determination.
6. Read and record COD measurement results (the instrument can store 20 results).
Notice
• Before measurement, please select the appropriate range (low range or high range) according to the estimated COD value of the water sample. If the COD value exceeds 1000mg/L, it needs to be diluted first.
• Ensure that the digestion temperature is accurately set to 165 +/- 1 ° C and the digestion time is 15 minutes to ensure complete reaction.
• Ambient Temperature of the instrument is 5~ 40 ℃, relative humidity should be < 85% and no condensation.
• Please use the specified special Reagent to ensure anti-chloride interference and catalytic effect.
• Please pay attention to safety when operating, Digester temperature is high, to avoid burns.
• Instrument Power Supply is AC220V +/- 10%/50Hz, please ensure stable power supply.
• Maintain and calibrate instruments regularly to ensure measurement accuracy.
