DINSEARCH 1-00 is an electromagnetic system for rapid, high resolution inspection of carbon steel tubes in heat exchangers, coolers, boilers and similar equipment. The probe is pushed and pulled through each tube in turn and signals are displayed which show the state of the tube.

The technique is not conventional eddy-current, remote field eddy-current or magnetic flux leakage. The wall of the tube is partially magnetised. Any loss of metal due to pitting, corrosion, erosion or other factors, results in local variations in the level of magnetisation within the tube wall. Sensors on the probe respond to these changes in the level of magnetisation within the tube wall.

Inspection speeds, typically 50 metres per minute, are similar to those achieved in non-ferrous tubes when using conventional eddy-current systems. This is much faster than IRIS ultrasonic systems and has the additional advantages that the tubes do not need to be perfectly clean or filled with water.

The traces from each tube are displayed on a computer screen, initially showing the whole length of the tube but with the facility to expand and view any section in great detail. The data is stored on a hard drive.

Applications

• Rapid, high resolution inspection of carbon steel tubes in heat exchangers, coolers, boilers and similar equipment.

Tubes from 15mm to 70mm o.d. in the usual range of wall thicknesses can be tested accurately at high probe travel speeds.