Reading Conversions
If only a few measurements are to be taken on a material other than
Steel, it may be easier to leave the calibration set for Steel and merely
convert the readings by multiplying by the Conversion Factor for the
material being measured. This method avoids unnecessary
recalibration.
Example.
The gauge is calibrated for Steel [5920 m/s], but the reading is
being taken on Copper [4700 m/s] :
T = t x V
COPPER
/ V
STEEL
= t x 4700 / 5920
= t x 0.794
thus : T = t x f [ where: f = V
COPPER
/ V
STEEL
]
where : T = true thickness of Copper being measured
t = actual reading obtained
f = Conversion Factor (from table)
V
COPPER
= Sound Velocity in Copper : 4700 m/s
V
STEEL
= Sound Velocity in Steel : 5920 m/s
The Conversion Factor f: is given for various materials in the
Table of Sound Velocities