Design and Implementation of Rain Gauge Measurement using Ultrasonic Sensor HC-SR04 (Case Study using Ombrometer Method)

Abstract

There are several types of rainfall measurement method, such as tipping bucket, siphon, rain water weight and other various methods. This research developed the alternative and affordable method to measure the rain gauge using ultrasonic sensor. The method used to convert the volume of collected rain water to the level of a rain gauge is Ombrometer method. Ultrasonic Sensor HC-SR04 is chosen as a sensor to measure the water level in the collected rain water tank because it categorized as a low-cost sensor. Measuring the level of rainfall using an ultrasonic sensor is influenced by the design of the reservoir tank and also the resolution of the ultrasonic sensor. This research found that the difference the measurement using ultrasonic sensor between ombrometer formula is sufficiently linear with the difference average at 32.63%. The lookup table method is implemented to linearize the measurement based on the ombrometer value method. By using the linearized value, the design is capable to measure light rain category because the design has the sensitivity/resolution measurement of rain gauge on 0.48 mm. This research also found that the average value of the measurement using the ultrasonic sensor for each measured volume water injected to the tank using this design and use this value as a trigger to send the actual measurement result to the users. All parameters from this system are sent using Wi-Fi connectivity to the server and can be monitored using Online Web Dashboard.