The use of high-frequency strain waves to perform examinations and note measurements is referred to as ultrasonic testing (UT). UT is commonly used for the detection or evaluation of flaws and characterization of materials, among other applications. A standard ultrasonic inspection system comprises a pulser/receiver, transducer, and display devices. The pulser/receiver produces electrical pulses of high voltage. The transducer generates high-frequency ultrasonic energy after being driven by the pulser. The reflected wave is then converted into an electrical signal by the transducer and is displayed on a screen. The reflected signal strength versus the time plot helps to glean information regarding the features of a defect. In this paper, we discuss the experiments performed in a laboratory setting to determine ultrasound-based biofilm sensor sensitivity in relation to changes in the surrounding environment of temperature, concentration, turbidity, and conductivity of the liquid passing through the system. The effect of the change in frequency of the sensors was also studied. The sensors being developed are small and compact, portable, can be placed on the outer walls of the desired surface, use digital signal processing techniques, and the biofilm presence on the inner walls of the surface can be monitored.
Keywords: biofilm; non-destructive; non-invasive; portable sensors; sensor systems; system.