DLM24 and DLM50 is new type level measure instrument which adopt Kay-Ray advance technology. It has eight single-chips and use echo method to do continuously measurement for liquid or solid. It can display the reading with centimeters, meters, percentage or inches and feet units according to user’s requirement. The instrument can output 4～20mA analog signal and three groups of alarm contact. It is easy to install and low maintain. The sensor has aluminum shell, stainless steel shell and Kynar ® fluorine plastics shell for user to choose. They can be used in the strong-corrosive media.