Dry chemistry method adopts reflection photometry or differential electrode method as measurement means, which mainly has the following characteristics: high accuracy and fast speed, and the test results can be made in 3 ~ 4min; Easy to operate without daily correction; There is no need to store any other reagent or prepare any solution; The sample does not need pretreatment, and the multilayer membrane has the function of selective filtration, so as to reduce the influence of interfering substances in the determination process; The amount of sample is small, and the water during reaction is supplied by the liquid components in the sample, so as to improve the sensitivity of determination; The multilayer diaphragm based on the principle of differential electrode method is disposable, so it has the advantages of conventional electrode method without its disadvantages; In some cases, it can replace wet chemical method for emergency samples, and can also be used for methodological evaluation of routine test results.

It can not only be used for qualitative examination, but also developed into semi quantitative and quantitative analysis methods. It has become an important method in clinical examination