an overview of the
chemical oxygen demand, or cod. it is the oxidation dose consumed when water samples are treated with certain strong oxidant under certain conditions. it is an indicator of the amount of reducing substances in water. the reductive substances in water include various organics, nitrite, sulfide, ferrous salts, etc. therefore, chemical oxygen demand (cod) is often used to measure the content of organic matter in water. the higher the chemical oxygen demand, the more heavily polluted the water.
this instrument uses a special reagent which contains a compound catalyst, which can accelerate the reaction and has anti-interference effect on chloride ions. after rapid redox reaction between water sample and special reagent, trivalent chromium ions are generated and their concentration is determined by spectrophotometry to obtain corresponding cod.
the cod rapid tester has been greatly improved in stability, accuracy, range and practicability. it can be used in chemical industry, petroleum, coking, paper making, metallurgy, brewing, medicine and so on. it can be widely used in various industries (industrial waste water, urban sewage, domestic sewage and surface water in rivers and lakes).
technical parameters and performance indicators
technical parameters:
l. determination method: rapid catalytic method (chromium method);
2. range of measurement: low range 0~150mg/l
high range of 100~1000mg/l (> 1000mg/l dilution test);
3. measurement error: 5~100 mg/l, absolute error: / - 5 mg/l; 100 mg/l~1000 mg/l, the relative error is less than or equal to or equal to 5%
4. eliminate temperature: 165 / - 1 ℃; digestion time: 15 minutes;
5. determination time: simultaneous determination of 9, 12 or 25 water samples in 30 minutes; (different quantity of water samples according to the configuration)
6. temperature < of error of plus or minus 1 ℃;
7. the temperature field uniformity of 2 ℃ or less;
8. the resolution time indicator error is no more than or 2%;
9. record storage: 20 measurement results can be stored.
performance index:
1. ambient temperature (5 ~ 40 ℃;
2. environmental humidity: relative humidity < 85% (no condensation);
3. power supply: ac220v plus or minus 10% / 50hz;