The TOFD method has assumed one of the leading positions in the control of long welds. Its popularity is conditioned by a number of advantages over other control methods, on which we will not dwell here.
But there is one significant drawback of TOFD equipment, which is mainly offered on the market of NDT instruments - a long signal cable connecting the scanner and the data analysis device. When controlling large objects, the length of signal cables can reach tens of meters, which makes them one of the weaknesses of the system - they are often damaged, and their replacement is costly. However, the main disadvantage of such long signal cables is a significant degradation of the signal to noise ratio. This makes the control of welds of great thickness difficult, and sometimes restricts. And even for thin welded joints, the increased noise level decreases the quality of the collected data and reduces the control reliability.
The TOFD MAN system developed by the OKO Group is free of such problem, thanks to the use of wireless technologies. The TOFD electronics, along with an 8-hour battery and a Wi-Fi module, are housed in the scanner operator's utility west.
When not in use, the scanner can be placed on the utility vest belt. Thanks to such arrangement, the length of the signal cables is from 2 to 5 m (which allows the scanner to be passed around the pipe, if required) and the level of induced noise is very low. The usage of low noise electronic components combined with advanced signal processing algorithms allow, even at a maximum gain of 110 dB to obtain a noise level within 20% of the vertical scale.
The wireless configuration of the system allows TOFD specialist with the PC system to be place in any convenient place in the Wi-Fi coverage range - usually 50-100 m, depending on the environment.
In addition a number of structural and functional features have been implemented in the TOFD MAN system:
On the scanner LED indicators of the data quality collection are placed- scanning speed and acoustic contact. Now the scanner operator can control these parameters himself and immediately scan the areas where the scanning speed was excessive or the acoustic contact deteriorated below the permissible value.
the TOFD 2.2 Lite scanner, which is normally supplied for the TOFD MAN system, is equipped with two main and central reverse handle, which facilitates its transfer around the pipe.
Magnetic wheels allow comfortable scanning of welded joints of objects from structural steels, plus fast fixed / unfixed stops – allow the scanner to be held on surfaces at any inclination angle.
A special fastening mechanism allows quick and easy change of probes and wedges.
the system software is a sequence of tabs that guide the operator through a step-by-step procedure for setting up, calibrating, monitoring and analyzing data.
For more detailed information and video on TOFD Man, please visit web-page