The BOD Tester is designed according to the differential pressure measurement principle, which simulates the biodegradation process of organic matter in nature, and the oxygen in the air above the flask continuously replenishes the dissolved oxygen consumed by the decomposition of organic matter in the sample. By monitoring the change in the air pressure in the flask, the BOD value of the biochemical oxygen demand of the sample was calculated by removing the CO2 generated during the decomposition of organic matter, which was generated. The BOD Tester produced by the company can choose from 1-30 days of incubation time and test six water samples at the same time. During the test, the BOD value of the current test is displayed directly on the screen, and the current test data can be viewed at any time. The instrument has an automatic storage function, which allows you to view the test result data at any time. The instrument also has a wireless printing function, which can print test data. The instrument can store 10 years of BOD5 result values and transmit the test data directly to the computer via wireless transmission.