Series smart electromagnetic flow meters consist of sensor and smart signal transducer. And it can be classified into two structures--- integral type and remote type according to the set-up form of the sensor and transducer. In terms of integral type electromagnetic flow meters, transducer and sensor directly assembles as a whole and can not be dissociated. It is usually used at the scene where the environmental situation is good. To remote type electromagnetic flow meters transducer composes a product through a special electric cable and sensor. The sensor is installed at the scene and the transducer is installed in the place where the conditions are good. It is usually used at the scene where the environmental situation is poor, such as underground wells, high temperature and the place where people can not reach.