With the introduction of these recent innovations, metering devices can be transformed into smart meters with abundant functions, and capable of transmitting data on electricity, water & gas remotely. A smart meter typically comprises of sensors, signal conditioning and collection, MCU, communication, display and smart card reader. The different smart meters require different sensors while energy meters need voltage and current sensors.
Water meters need flow sensors to measure flowing fluid. Heat meters need both flow sensors and temperature sensors. Gas meters need airflow sensors, temperature sensors and pressure sensors. Signal Conditioning and collection blocks are used to adjust and amplify the small signals from sensors and convert into digital signals that MCU can use. MCU is the core of a smart meter, responsible for the control of all the functions such as display, communication, calculation based on measured data, smartcard reading, and time-division charge. Smart meters usually use LCD for the display of readings and alarm information. Depending on different requirements and management modes, one of the wired communication methods such as CAN and RS485 can be selected for smart meters, and a wireless communication method such as Zigbee can be adopted. Smart card readers on smart meters make it possible to realize prepaid usage for utilities and customers.