1Soil organic carbon digestion constant temperature heaterApplicable standards:

This product is suitable for national standards《HJ 615-2011 Determination of soil organic carbon - Potassium dichromate oxidation spectrophotometric method

IISoil organic carbon digestion constant temperature heaterProduct Introduction:

Soil organic carbon constant temperature heater is a heating and digestion device that uses electric heating method. It adopts a new type of temperature controller, with fast heating speed, constant and uniform temperature, easy operation, and is a new experimental instrument product.

TC-12HThe type soil organic carbon digestion constant temperature heater adopts digital setting, displays heating temperature, automatically controls heating temperature, can set constant temperature heating time, and can query the remaining time of timing. This device has a fast heating speed, constant and uniform temperature, low power consumption, simple operation, stable and reliable performance. It has been widely used for soil organic carbon determination in industries such as environmental protection, agriculture, third-party testing, and higher education.

IIISoil organic carbon digestion constant temperature heaterTechnical features:

1The constant temperature heater adopts digital temperature control, and the time can be set arbitrarily, making it easy to operate

2Automatically calculate heating reflux time, heating reflux time2After the hour arrives, the instrument automatically shuts down.

3Low temperature drift, energy-saving, water-saving, low power consumption, fast heating speed.

4Made with new digital temperature control devices and processing technology, each heating hole is uniformly heated at a constant temperature.

5Sewage cooling makes operation more convenient and energy-saving.

6Add an alarm prompt function for the end of digestion.

7Small size and space occupation

8. Comes with a stoppered digestion tube with 50mL and 100mL scale lines.

4、 Technical indicators

1Temperature adjustable range:32℃~300℃

2Constant temperature accuracy:±2℃

3Heating time: (200℃)<30min

4Power consumption:1.3kw

5Number of samples heated simultaneously:12(Other specifications and hole numbers can be customized)

6Power supply voltage:AC220V±10％，50Hz

7Size:42cm*30cm*12cm(Long)*wide*High)

8Working environment: Temperature0-50℃, humidity<85%RHIn environments without corrosion or strong magnetic interference

9Equipped with a scale plug digestion tube

5、 Appendix: Determination of soil organic carbon - Potassium dichromate oxidation spectrophotometric method

1Scope of application: This standard specifies the determination of potassium dichromate oxidation of organic carbon in soil-Spectrophotometric method. This standard is applicable for the determination of organic carbon in air dried soil. This standard is not applicable to chloride ions（Cl-）Content greater than2.0×104 mg/kgDetermination of Salinized Soil or Salinized Soil. When the sample size is0.5gThe detection limit of this method is0.06%(Calculated by dry weight), the lower limit of determination is0.24%(Calculated by dry weight).

2Normative References: This standard refers to the following documents or their clauses. Any referenced document without a specified date shall have its valid version applicable to this standard.HJ 613 Determination of soil dry matter and moisture by gravimetric method

HJ/T 166 Technical specifications for soil environment monitoring

3Method principle: Under heating conditions, excessive potassium dichromate is added to the organic carbon in the soil sample-Oxidation of hexavalent chromium in potassium dichromate by sulfuric acid solution（Cr6+）Reduced to trivalent chromium（Cr3+）Its content is directly proportional to the organic carbon content in the sample585 nmMeasure absorbance at wavelength based on trivalent chromium（Cr3+）Calculate the organic carbon content based on its content.

4Interference and elimination4.1 Ferrous ions in soil（Fe2+）It will lead to higher results in the determination of organic carbon. Soil samples can be spread out during the sample preparation process2～3 cmThick thin layer, fully exposed to air to allow ferrous ions（Fe2+）Oxidation to trivalent iron ions（Fe3+）To eliminate interference.4.2 Chloride ions in soil（Cl-）It can lead to high measurement results of soil organic carbon, and interference can be eliminated by adding an appropriate amount of mercury sulfate.

5Unless otherwise specified, analytical grade chemical reagents that meet national standards are used for analysis, and experimental water is used25Conductivity at ℃≤0.2mS/mDeionized water or distilled water.

5.1 Sulfuric acid:ρ（H2SO4）=1.84 g/ml.

5.2 Mercuric sulfate

5.3 Potassium dichromate solution: （K2Cr2O7）=0.27 mol/LcWeighing80.00 gPotassium dichromate is dissolved in an appropriate amount of water and then transferred to1000 mlFill the volumetric flask with water and shake well. The solution is stored in a reagent bottle,4Store at ℃.

5.4 Glucose standard solution:ρ（C6H12O6）=10.00g/LWeighing10.00 gDissolve glucose in an appropriate amount of water and transfer it to1000 mlFill the volumetric flask with water and shake well. The solution is stored in a reagent bottle and has an expiration date of one month.

6Instruments and equipment

6.1 Spectrophotometer: equipped with585 nmWavelength and equipped with10 mmColoring dish.

6.2 Balance: accuracy of0.1 mg.

6.3 Thermostatic heater: Temperature control accuracy is135±2℃. The constant temperature heater is equipped with heating holes, and the hole depth should be higher than the liquid level in the dissolution glass tube10 mmAnd the exposed heating hole of the glass tube with a stopper digestion is about150 mm.

6.4 Dissolving glass tube with stopper: equipped with100 mlScale line, with a diameter of35～45 mmNote: The outer wall of the stoppered digestion glass tube must be able to tightly adhere to the inner wall of the heating hole of the constant temperature heater, otherwise complete digestion cannot be guaranteed.

6.5 Centrifuge:0 ~3000 r/min, equipped with100 mlCentrifugal tube.

6.6 Soil sieve:2 mm（10Purpose)0.25 mm（60The object is made of stainless steel material.

6.7 Common laboratory instruments and equipment