The Binatech Blog News
In this section of the site contributing authors submit interesting articles relating to the various services, industries and research & development efforts of Binatech.
There are several reflector types commonly used as a basis for establishing system performance and sensitivity. Included among them are spheres and flat-bottom holes (FBH), notches, side-drilled holes (SDH), and other special purpose or designs. Table 1 summarizes these reflectors characteristics and uses. Spherical reflectors are used most often in immersion testing for assessing transducer sound fields. Spheres provide excellent repeatability because of their omnidirectional sound wave response. The effective reflectance from a sphere is much smaller than that received from a flat reflector of the same diameter due to its spherical directivity pattern. Flat reflectors are used as calibration standards in both immersion and contact testing. They are usually flat-bottom drilled holes of the desired diameters and depths. All flat reflectors have the inherent weakness that they require careful sound beam-reflector axis alignment. Generally, if a discontinuity echo amplitude is equal to the amplitude of the calibration reflector, it...
