A maintenance engineer uses an ultrasound probe to examine a uniform concrete support. Each pulse travels in a straight line from the probe to a reflecting surface and back to the probe.
The probe is first placed on a calibration block made from the same concrete as the support.
| Calibration quantity | Value |
|---|---|
| Distance from the probe to the opposite face | 0.60 m |
| Echo return time from the opposite face | 0.30 ms |
The probe is then placed on the support. An internal joint and the opposite face are on the same straight line beneath the probe.
| Reflecting surface | Echo return time |
|---|---|
| Internal joint | 0.45 ms |
| Opposite face | 0.95 ms |
Calculate the speed of ultrasound in the concrete.
Calculate the distance between the internal joint and the opposite face of the support.