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## Time of Flight Visualiser:

Since around the year 2000, both phased array and time of flight technology have been commonly used as affordable, reliable ultrasonic inspection methods

The calculator below helps to visualise the 6dB beam coverage that a pair of TOFD probes can achieve within a welded plate. as well as plotting the coverage, the calculator also returns the time/position of the lateral wave and backwall echo, both useful when configuring a TOFD scan

The following formulae are used to calculate the TOFD beams:

$LW=2s/c+2to$

Where:

LW = time taken for lateral wave to travel from probe to probe (µs)

s = distance of probe to weld centreline

c = material velocity (mm/µs)

t0 = wedge delay (µs)

$BW=2*(s^2+D^2)^0^.^5/c+2to$

Where:

BW = time taken for the sound to travel from the probe to backwall back to probe (µs)

s = distance of probe to weld centreline

c = material velocity (mm/µs)

D = material thickness (mm)

t0 = wedge delay (µs)

As well as these fundamental formulae, basic snells law and beam spread calculations are used to calculate and plot the 6dB beam divergence from the beam centreline.