Kjeldahl nitrogen analyzer is an instrument that calculates the protein content by measuring the nitrogen content in the sample based on the principle that the nitrogen content in the protein is constant. Because the method for measuring and calculating protein content is called Kjeldahl method, it is called Kjeldahl nitrogen analyzer.

The difference between Kjeldahl protein nitrogen analyzer and combustion method nitrogen analyzer:

1. Different principles: Kjeldahl method is an absolute measurement; combustion method is a relative measurement.

2. Different measurement objects: Kjeldahl method measures ammonia nitrogen; the combustion method measures total nitrogen.

3. Different standards: Kjeldahl method is the international standard for all samples; the combustion method is the reference method.

4. Different sample sizes: Kjeldahl method is constant analysis; combustion method is trace analysis.

5. Operating costs: The reagent cost for Kjeldahl method is lower than the cost of consumables for the combustion method.

6. Analysis speed: Kjeldahl nitrogen analyzer is slower than the combustion method nitrogen analyzer.

7. Working environment: Kjeldahl nitrogen analyzer contains a large number of chemical reagents; combustion method nitrogen analyzer is relatively environmentally friendly.

Kjeldahl nitrogen apparatus is widely used to analyze the nitrogen content or protein content of food, crops, seeds, soil, fertilizer and other samples. It has the characteristics of high cost performance and simple operation, and is very suitable for routine testing in laboratories and inspection institutions.