Kjeldahl nitrogen analyzer is an instrument that calculates the protein content by measuring the nitrogen content in the sample based on the principle of constant nitrogen content in protein. Because the method of protein content measurement and calculation is called Kjeldahl method, it is called Kjeldahl nitrogen analyzer, also known as nitrogen analyzer, protein analyzer, and crude protein analyzer.
 
Kjeldahl nitrogen analyzer uses the Kjeldahl method to detect the content of ammonia, protein nitrogen, phenol, volatile fatty acid, cyanide, sulfur dioxide, ethanol, etc. in grains, food, feed, water, soil, sludge, sediment and chemicals. It is widely used in the analysis of nitrogen or protein content of food, crops, seeds, soil, fertilizers and other samples, and is very suitable for routine testing of laboratories and inspection agencies.
 
At present, Kjeldahl nitrogen analyzers on the market can be divided into four types, Kjeldahl nitrogen determination glass device, semi-automatic nitrogen analyzer, automatic nitrogen analyzer and full automatic nitrogen analyzer. Among them, Kjeldahl nitrogen determination glass device is relatively cheap. However, the operation is not safe and the detection range is relatively narrow. The semi-automatic nitrogen analyzer can automatically complete the distillation, but requires to manually add some reagents, so it is not as convenient as automatic nitrogen analyze or full automatic nitrogen analyzer in operation. The automatic nitrogen analyzer automatically adds various reagents and completes the distillation, but the operation process still requires personnel supervision and participation, which is suitable for enterprises and units that have less high requirements for operation. The full automatic nitrogen analyzer is a highly automated instrument product among the four types of Kjeldahl nitrogen analyzers. It is an integrated nitrogen analyzer for distillation and titration, which is not only more convenient and safer to operate, but also can effectively reduce human error, greatly improving the efficiency of protein determination and the accuracy of determination results.
 
Although from the perspective of safety, operation, and detection results, the full automatic nitrogen analyzer is comprehensive and has obvious advantages, its price is relatively much higher than other types. At present, these four types of Kjeldahl nitrogen analyzers are produced and sold on the market, which shows that these four types of Kjeldahl nitrogen analyzers are all available in the market. Therefore, when choosing a  Kjeldahl nitrogen analyzer, users should make a choice based on their own experimental needs and economic level, so that the instrument can really be effective in actual work and avoid waste of resources.