This research presents an ultrasonic strip waveguide sensor with various reflector embodiments, including rectangular notches, single, and multiple bends. The ultrasonic waveguide sensor concept is a non-destructive and non-invasive method to measure material properties in elevated temperatures, where conventional techniques often fail. This ultrasonic sensor technique measures the surrounding temperature of the waveguide and its temperature-de
pendent elastic moduli using the symmetric (S0) wave mode. Initially, we performed the Finite Element Method (FEM) simulations using Abaqus CAE software to find a better ultrasonic
reflector configuration and its dimension based on the ultrasonic waveguide (S0 mode) signal behavior. The simulation uses a rectangular strip waveguide (stainless steel) with a thickness
of 0.5 mm, a width of 3 mm, and a length of 1000 mm. The S0 mode was excited using a Hanning pulse tone burst signal at one end of the waveguide. Then, FEM studies revealed that the reconfigurable bend reflector (radius 3 mm) is better than rectangular reflector configurations for designing the ultrasonic sensor to obtain better reference reflection. Then, ultrasonic-guided wave experiments were conducted at different temperatures using the same dimension of the stainless-steel strip as a waveguide using the pulse-echo approach with an ultrasonic shear transducer at one end of the waveguide. We considered the ultrasonic parameter time of flight difference to calibrate the sensor based on the surrounding temperature. Also, temperature-dependent elastic moduli were measured, resulting in a maximum measurement error of 3% compared to literature data. The developed novel waveguide technique comprising non-destructive method can easily measure the elastic moduli compared to conventional destructive type testing methods, specimens are reusable, monitoring the components in service, and simple and cost-effective technique for monitoring various industrial components like power plants, oil, and Petro-chemical industries.