Electromagnetic Ultrasonic Thickness Gauge

Ultrasonic stress measurement technology is based on the acoustic elastodynamic effect, which relies on the characteristic that the propagation speed of elastic waves in solids depends on mechanical stress.

Electromagnetic ultrasonic stress sensors generate horizontal shear waves with two orthogonal polarizations through the material, where the horizontal polarization ultrasonic wave velocity is a linear function of the residual stress. Portable electromagnetic ultrasonic thickness gauges are technologically supported, thus the birefringence caused by stress can be measured by the sound waves.

Uncoupled electromagnetic ultrasonic transducers generate sound waves on the material surface that allow for accurate measurement of the transit time (TOF) of two orthogonal polarized shear waves. Portable electromagnetic ultrasonic thickness gauges available, unaffected by the thickness of the coupling agent layer. The "B" value for birefringence refers to the sum of the material's intrinsic anisotropic B0 and the residual stress Bσ, portable electromagnetic ultrasonic thickness gauges, proportional to the biaxial stress field, with the acoustic compliance constant "K" value calculable through experimentation.

This method provides the average stress magnitude corresponding to the thickness.

Electromagnetic Ultrasonic Thickness Gauge

In practical applications, EMAT technology offers distinct advantages over traditional piezoelectric ultrasonic technology and possesses a series of characteristics that cannot be replaced by piezoelectric ultrasonic technology:

(1) Fast testing speed - The testing speed of traditional piezoelectric ultrasonic is generally around 10 meters per minute (domestic equipment), while EMAT can reach up to 40 meters per minute, even faster.

(2) Long-range Sound Wave Propagation - The ultrasonic waves generated by EMAT in steel pipes or rods can propagate around the workpiece for several or even dozens of rotations. During longitudinal defect detection in steel pipes or rods, neither the probe nor the workpiece needs to be rotated, simplifying the mechanical structure of the flaw detection equipment.

(3) Fewer channels and probes used: The EMAT flaw detection equipment uses fewer channels and probes than piezoelectric ultrasound to achieve the same functionality. This is particularly evident in plate EMAT flaw detection equipment, where piezoelectric ultrasound requires dozens of channels and probes to inspect the surface, whereas EMAT only needs four channels and the corresponding number of probes.

Eddy Current Ultrasonic Thickness Gauge

Compared to conventional ultrasonic testing, electromagnetic ultrasonics offers the following advantages:

① Contactless detection, no coupling agent required, capable of penetrating coatings. The energy conversion of EMAT is directly conducted within the skin depth of the workpiece surface.

Therefore, the skin depth can be regarded as a piezoelectric crystal, as the skin depth is the surface layer of the workpiece. Consequently, the portable electromagnetic acoustic thickness gauge after-sales service requires that the ultrasonic waves generated by EMAT do not require any coupling medium.

② Fast testing speed. The testing speed of traditional piezoelectric ultrasonic is generally around 10 meters per minute, whereas EMAT can reach up to 40 meters per minute, even faster.

Portable Electromagnetic Ultrasonic Thickness Gauge - Technical Support for Portable Electromagnetic Ultrasonic Thickness Gauge - Provided by Beijing Han Gu Precision Instrument Co., Ltd. Beijing Han Gu Precision Instrument Co., Ltd. boasts strong capabilities and reliable reputation, having accumulated a large number of loyal customers in the industry of instruments, components, and equipment in Changping District, Beijing. Beijing Han Gu, with a spirit of continuous improvement and innovative thinking, joins hands with you to stride towards brilliance and create a beautiful future together!