This study investigates the developments of a new experimental setup for the detection of air and solid blockage inside pipes. Earlier research utilized a hollow capillary composed of thin plastic material to detect the existence of air inside the pipeline. The experimental setup is even easier for detecting solids. Prior to the experiment, a simulation using the finite element method (FEM) was conducted to investigate the behavior of acoustic pressure in two phases, namely, liquid solid and liquid gas. An ultrasonic sensor circuit consisting of a transmitter, a receiver, and signal conditioning circuits was constructed. For this experiment, an acrylic pipe with a diameter of 110 mm and a thickness of 5 mm was used, while polyvinyl chloride (PVC) pipes were used as the blockage subject. Two scenarios were considered, which are: a PVC with water inside, and a PVC with air inside. Based on the experimental results, the acoustic wave energy was more attenuate as the size of the blockage inside the pipeline increased, and air is a great discontinuity to ultrasonic transmission.
