Kjeldahl nitrogen analyzer is an instrument to calculate the protein content by measuring the nitrogen content in the sample according to the principle of constant nitrogen content in protein. Because the method of protein content measurement and calculation is called Kjeldahl nitrogen determination method, it is called Kjeldahl nitrogen analyzer, also known as nitrogen analyzer, protein analyzer and crude protein analyzer.
 
FAQ of Kjeldahl nitrogen analyzer:
1. What are the common Kjeldahl nitrogen analyzers in the market?
There are many types of Kjeldahl nitrogen analyzers in the market, and the most common ones are as follows:
① Semi automatic nitrogen analyzer: It only has the distillation part, doesn't include  titration part，and requires manual titration.
② Automatic Kjeldahl nitrogen analyzer: distillation and titration are integrated design. After the sample is completely digested, it is put into the instrument that automatically adds water, alkali, acid, titration and prints the results. The whole experimental process does not need human intervention, which greatly reduces the workload of laboratory personnel, improves work efficiency, and contributes to more accurate test results.
2. What industries are nitrogen analyzers mainly used in?
The nitrogen analyzer is mainly used to determine the content of nitrogen and crude protein in the sample. It is mainly used for the relevant experiments in food, feed, agriculture, scientific research institutes, medicine, universities, daily chemicals, soil fertilizers, etc., in which Kjeldahl method is used to determine nitrogen and crude protein in samples.
3. What are the requirements for water quality in the operation of Kjeldahl nitrogen analyzer?
Distilled water or pure water shall be filled in the distilled water bucket of Kjeldahl nitrogen analyzer. If the machine is not used for a long time, the water in the distiller shall be discharged.
4. What's the cause if Kjeldahl nitrogen analyzer starts without sound?
If the red light in the power switch of the machine is on, it means that the safety tube in the nitrogen analyzer is burnt out, and the safety tube is located in the black shell 5 cm away from the power switch interface inside the machine.
5. How to solve the problem that there is no water in the distiller when Kjeldahl nitrogen analyzer is started?
After starting up for half a minute, check whether the distilled water bucket leaks. If it can be filled with air, it is normal. Check whether the water level in the distilled water bucket  exceeds one third, and if not enough, add more. Check the position of the distilled water bucket, if it is lower than the table on which the instrument is placed, the pressure is not enough to add water. Check whether the air inlet and liquid inlet pipes of the distilled water bucket are connected correctly, and bubbles and sounds will be generated if they are incorrectly connected. Check whether the drain valve is closed.
 
Kjeldahl nitrogen analyzer uses Kjeldahl method to detect the contents of ammonia, protein nitrogen, phenol, volatile fatty acids, cyanide, sulfur dioxide and ethanol in grains, food, feed, water, soil, sludge, sediment and chemicals. It has a very good cost performance, and only the titration process needs manual operation, which is very suitable for routine detection in laboratories and inspection institutions. It is widely used to analyze the nitrogen content or protein content of food, crops, seeds, soil, fertilizer and other samples.