Ultrasonic Testing Services
Basic Principle: It performs on pulse-echo method. The pulse of sound coming from transmitter is radiated in a beam by a given medium at a special velocity or speed, in a predictable direction, and they will be reflected when they encounter a boundary with different medium.
Frequency: All the sound waves oscillate at a special frequency, cycles per second or number of vibrations, which we experience as pitch in the known audible sound range. Human ears can respond to the sound vibrations that have frequencies in the range of 20Hz - 20kHz. While a large number of ultrasonic flaw detection applications use frequencies between 500 KHz - 10 MHz. At frequencies in megahertz range, sound energy does not move efficiently through air, or other gasses; it travels freely through common engineering materials and most liquids.
Velocity: The speed of a sound wave differs, counting on the medium through which it travels, affected by the density of medium and elastic properties. In steel, the sound wave velocity is 6*1000000 mm/sec.
Wavelength: Any wave type will have a related wavelength, which is distance between any two corresponding points in the cycle of wave, as it travels through with a medium. Wavelength is associated to velocity and frequency by the following:
λ = v/f, where λ = wavelength; v = sound velocity; f = frequency.