measuring principle

Organic matter in water is oxidized, which converts Cr^6＋Restore to Cr^3＋Determination of trivalent chromium (Cr) produced by reduction of potassium dichromate at a wavelength of 610nm³⁺）The absorbance, COD value, and trivalent chromium (Cr)³⁺）The increase in absorbance is directly proportional to trivalent chromium (Cr)³⁺）Convert the absorbance to the COD value of the sample; Determination of hexavalent chromium (Cr) reduced by potassium dichromate at a wavelength of 420nm⁶⁺）The absorbance, COD value, and hexavalent chromium (Cr)⁶⁺）The decrease in absorbance is directly proportional to hexavalent chromium (Cr)⁶⁺）Convert the absorbance to the COD value of the sample.

Measurement steps

Add 2ml of sample → Dissolve in a digestion device for 15 minutes → Directly call the built-in curve measurement of the COD analyzer

ET3150B Dissolver

It can achieve the digestion function of various chemical reactions such as COD (165 ℃), total phosphorus, total nitrogen (105 ℃), ammonia nitrogen, fluorine, etc
Capacity: 24 pieces, Φ 16 × 100mm

High temperature accuracy, temperature accuracy: ± 1 ℃ Working temperature: 0~50 ℃ ◆ Dissolution temperature 165 ℃± 1 ℃ ◆ Automatic timing and temperature control. Automatic alarm and shutdown ◆ Data display: LCD digital display in Chinese ◆ It can achieve the digestion function of various chemical reactions such as COD, total phosphorus, total nitrogen, ammonia nitrogen, fluorine, etc., and digest 24 samples at the same time Stability: ± 1 ℃ Test tube (colorimetric tube) specification: 16 * 100mm ◆ Digital display of temperature and time Time setting range: 1-1860 minutes (31 hours) ◆ Easy to operate, safe and reliable, maintenance free Fast heating speed: can be heated from 20 ℃ to 165 ℃ within 10 minutes

ET1151M

The ET1151M Chemical Oxygen Demand (COD) analyzer is a microprocessor controlled, LED light source filter analyzer suitable for laboratory or on-site testing of COD, TN, and TP. This instrument can directly call the internal curves of the program, and also allows users to store their own standard curves. Built in COD (chemical oxygen demand), TN (total nitrogen), TP (total phosphorus), ammonia nitrogen, fluoride 5 testing programs and 6 testing curves.

Power supply: 220V, 50Hz ◆ Environmental temperature: 5-50 degrees Celsius Relative humidity: 20% — 85% Technical requirements for visible spectrophotometer: ◆ Wavelength range: 420nm, 610nm ◆ Wavelength accuracy: ±2nm ◆ Light source lamp: Light emitting diode (LED) Indication error: within ± 8% ◆ Repeatability: RSD≤3% ◆ Stability: The absorbance value changes by less than 0.005A within 20 minutes Reading format: absorbance, transmittance, concentration ◆ Automatically select test wavelength

Total nitrogen (TN) measurement:Nitrogen in water is converted into nitrate, which reacts with chromogenic acid under acidic conditions to form a yellow compound. The increase in absorbance of the yellow compound is measured at a wavelength of 420nm and converted to the concentration of total nitrogen.

Total phosphorus (TP) measurement:Phosphorus in water is converted into orthophosphate, which reacts with molybdate to form phosphomolybdic acid under acidic conditions. It is then reduced by ascorbic acid to form a blue complex. The increase in absorbance of the blue complex is measured at a wavelength of 610nm and converted to the concentration of total phosphorus.

Supporting reagents

The reagent has been packaged and added directly to the water sample for digestion.
The digestion tube is a colorimetric tube, which simplifies the analysis process.
◆ Efficient, convenient, and safe operation.
◆ There are also bottled reagents that users can self package.