Abstract
In this paper we shall describe some of our work in developing industrially viable non-contact ultrasonic measurements. For most materials, non-contact ultrasonic techniques are typically not as efficient at generating or detecting ultrasound as conventional contact methods. However non-contact methods can offer some distinct advantages over contacting methods including their suitability to a range of online measurements. This is because the measurements do not require an acoustic couplant and can be applied to hot or moving samples in hostile environments. These benefits also make the techniques suitable for automation and potentially give increased reliability. The methods described in the paper can and have been used in industrial environments or on industrial samples. The paper will concentrate on two of our research areas, the first being ElecroMagnetic Acoustic Transducers (EMATs) and the second being laser generation / detection of ultrasound. Operation principles of these two techniques will be discussed and illustrated by describing some applications of this technology to various testing problems.
