What distance between the probes should be used if the specimen thickness H is 15mm and the probe angle is 60 ? Note that the beam is usually targeted at a depth of 2/3 of the specimen thickness. What should the separation of the probes be in a Titanium test piece with thickness H=15mm if we want to avoid any shear waves arriving too early? The velocities of compression and shear waves in Titanium are 6130 and 3182ms1 respectively. What distance between the probes should be used if the specimen thickness H is 15mm and the probe angle is 60 ? Note that the beam is usually targeted at a depth of 2/3 of the specimen thickness. What should the separation of the probes be in a Titanium test piece with thickness H=15mm if we want to avoid any shear waves arriving too early? The velocities of compression and shear waves in Titanium are 6130 and 3182ms1 respectively