84results about How to "Small temperature fluctuation range" patented technology

The invention relates to pedology and ecology, in particular to a method for determining organic matters in soil. The method comprises the steps of levigating and sieving air-dried soil, then placing the soil into a conical flask, sequentially adding a potassium dichromate solution and sulfuric acid into the conical flask, placing the conical flask into a drying box which is already preheated to 100 to 125 DEG C for 30 to 90 minutes, taking out the conical flask, cooling the conical flask to room temperature, performing titration, and calculating the content of organic matters. The heating of the drying box is used for substituting the traditional oil-bath heating, and the conical flask is used for substituting a sterilizing tube. When the heating temperature of 115 DEG C and the heating time of 30 minutes are determined, compared with the organic matter result determined by existing precise element analyzers, the standard deviation and deviation ratio are respectively 2.18 and less than 6 percent; and the correlation of the content of organic matters determined in two methods reaches up to 0.998; compared with the traditional oil-bath heating method, the precision is improved by about 12 percent. By adopting the method, in the determining process of the soil organic matters, uniformity in heating is achieved, the temperature fluctuation range is small, and the precision of a test result is high.