CODG-3000 COD Chromium Method Online Automatic Monitoring Instrument Introduction: The water sample passes through a peristaltic pump and a nine way valve. Under the action of digestion solution and acid solution, the mixture of water sample, potassium dichromate solution, mercury sulfate (mercury sulfate can eliminate the interference of chloride ions in the water sample, as chloride ions can form very stable mercury chloride with mercury ions), and silver sulfate solution (silver sulfate can be added as a catalyst to more effectively oxidize linear fatty compounds) is heated to 165 ℃. After the organic matter in the solution is oxidized by dichromate ions, the color will change. The analyzer detects this color change and converts this change into a COD value to output. The amount of dichromate ions consumed is equivalent to the amount of oxidizable organic matter. Features: 1. Choose the reagent sampling timing, with flexible and diverse channels, versatile functions, small size, easy maintenance, and long lifespan. 2. The negative pressure suction of the peristaltic pump always creates an air buffer zone between the reagent and the pump tube, avoiding corrosion of the pump tube; At the same time, it makes reagent mixing more concise and flexible. 3. Accurate measurement of reagents is achieved through a visual photoelectric system, overcoming quantitative errors caused by wear of peristaltic pump tubes; At the same time, precise quantification of trace reagents was achieved, with each dose only 1.5 milliliters, greatly reducing the amount of reagents used. 4. The high-temperature and high-pressure digestion system accelerates the reaction process and overcomes the corrosion of equipment caused by corrosive gas volatilization in open systems. 5. Adopting imported new transparent polytetrafluoroethylene hoses with a diameter greater than 1.5mm, the probability of water sample particle blockage is reduced. Technical parameters: Method basis: National standard GB11914-89 "Water quality - Determination of chemical oxygen demand - Potassium dichromate" Measurement range: 0-15000 mg/L COD (scalable) Accuracy: not exceeding ± 10% when ≥ 100mg/L; ＜ At 100mg/L, not exceeding ± 8mg/L Repeatability: not exceeding ± 10% when ≥ 100mg/L; ＜ At 100mg/L, not exceeding ± 6mg/L Indicating error: not exceeding ± 10% Measurement cycle: The measurement cycle is 50 minutes, and according to the actual water sample, the digestion time can be arbitrarily modified within 5-120 minutes Sampling period: time interval (adjustable from 55 to 9999 minutes) and hourly measurement mode Calibration cycle: 1-99 days, adjustable at any time interval Maintenance cycle: Generally once a month, about 30 minutes each time Output: 4-20mA (2 channels) RS232, RS485 Relay output: 2 control relay outputs Environmental requirements: Indoor with adjustable temperature, recommended temperature+5-28 ℃; Humidity ≤ 90% (without condensation) Power supply: AC220 ± 10% V, 50 ± 10% Hz, 5 A Dimensions: Height 1750 x Width 500 x Depth 450 mm
Introduction: The water sample passes through a peristaltic pump and a nine way valve. Under the action of digestion solution and acid solution, the mixture of water sample, potassium dichromate solution, mercury sulfate (mercury sulfate can eliminate the interference of chloride ions in the water sample, as chloride ions can form very stable mercury chloride with mercury ions), and silver sulfate solution (silver sulfate can be added as a catalyst to more effectively oxidize linear fatty compounds) is heated to 165 ℃. After the organic matter in the solution is oxidized by dichromate ions, the color will change. The analyzer detects this color change and converts this change into a COD value to output. The amount of dichromate ions consumed is equivalent to the amount of oxidizable organic matter.
