*Ultrasonic Pulse Velocity (UPV)*

Ultrasonic pulse velocity (UPV) testing was used to determine the integrity and quality of the mortar, structure concrete, or stone (up to 6 feet thick) by measuring the speed and attenuation of an ultrasonic wave passing through the specimen being tested. The method consists specifically of measuring the time of travel of an ultrasonic pulse passing through the sample being evaluated as per EN 12504-4:2021 [5]. Comparatively a higher velocity is obtained when material quality has sufficient density, uniformity, homogeneity, etc.

Determining the time as well as the distance the wave was sent through the sample in formula 2 allows us to determine the value of UPV used.

$$V\_p = \frac{d}{t} \text{ m/s} \tag{2}$$

where *t* and *d* are, respectively, the travel time and the distance. The UPV (*Vp*) is expressed in m/s.
