Inspection of highly attenuating materials such as CFRP and Fiberglass requires using low frequency transducers to improve penetration and signal-to-noise ratio.

Also Air-Coupling techniques and Lamb-Waves Inspection require low frequency arrays. 

All of our standard SITAU equipments are available in LF (Low frequency) versions, to be used with arrays between 30 kHz and 2 MHz.

The SITAU systems allow to acquire with two different modes.

"Phased Array" mode

In emission, the hardware applies the programmed focal laws for each line of the B-Scan image, allowing focusing at any depth and deflecting the beam at any angle.

In reception, the hardware applies the programmed focal laws, getting, for each line of the B-Scan image, an A-Scan signal obtained by applying the focal law delays to each one of the elements of the active aperture.

"Multichannel" Mode

In emission, the hardware applies the programmed focal law for each line of the B-Scan image, allowing focusing at any depth and deflecting the beam at any angle.

In reception, no processing is performed with the signals received by each element of the active aperture, for each acquisition, the SITAU system returns all the A-Scan signals received by each element of the active aperture.

In this mode the SITAU system operates as a multi-channel system allowing access to the A-Scan signals from each channel, this feature allows the user develop Synthetic Aperture Focusing Techniques (SAFT), Full Matrix Capture (FMC), Total Focusing Method (TFM) or Sampled Phased Array (SPA).

Emitter:

-       Fixed pulse amplitude (-100 V) or programmable form -20 V to -190 V

-       Programmable pulse width from 100 ns to 25.5 us, with a resolution of 100 ns

-       Burst mode up to 256 pulses

-       Programmable coded excitation (16 bits)

-       Encoder trigger or external input signal trigger

Receiver:

-       Bandwidth from 30 KHz to 2 MHz (- 3 dB)

-       Programmable sampling frequency from 157 KHz to 40 MHz

-       Programmable Gain  up to 100 dB

-       TGC curve up to 2048 points

Signal processing:

-       Auto-focus

o     Immersion, the system auto-detects the material surface, and auto-configures the focal laws to get the image focused into the material.

o     With wedge, the SITAU system auto-detects the wedge geometry, and auto-configures the focal laws.

-       Grain Noise Reduce Filter.

Removes, in real-time, the material grain noise using the Phase Coherence Technique.

-       EMI Filter.

o     Removes, in real-time, the impulsive noise

o     Improves flaw detection and reduces the production of false alarms

o     Keeps a high dynamic range in noisy environments for C and D-scans

-       Dynamic Depth Focusing in real-time applying a focal laws per each sample of each A-Scan of the B-Scan image (hardware implemented).

-       Band-Pass filter with programmable cut-off frequencies.

-       Scan compression with Non-Peak-Loss compression algorithm, up to 128:1 compression rate.

-       Average (2, 4, 8, 16, 32, 64, 128, 256)

-       Single focus programmable and independent for emission and reception, and independent for each scan line.

-       Programmable hardware and software gates to detect of the maximum, minimum, positive edge or negative edge

-       Acquisition information data in real-time: A-scan, B-scan, peak position and amplitude (gates), encoders count.