Design and Construction of Water Level Measurement System Accessible through SMS

Water level measurement data is very important in some water-related fields. An automatic water level measurement system is needed to prevent the difficulties when one does the measurement manually. This system uses AT89S51 micro controller to control the system, ultrasonic sensor to measure the water level, and SIM300C GSM modem to receive and send SMS. The system can measure the water level and give measurement report upon requested SMS. This system can be placed in many places because it only needs the initial setting via SMS, based on its installation condition at those places. The average measurement error of this system is 3,74%. This system can measure the water level up to 432 cm and work at 4 - 4,5 V supply voltage range.