Batches of coiled steel often need to be inspected for compliance with thickness specifications. Conventional measurements are limited to the cut edges at the head of the coil. Ultrasonic thickness measurements, on the other hand, are made from one side only - the exposed side - making it possible to monitor the thickness over the entire width of the coil. Since the thickness can vary as much as 0.002 to 0.004 inch (0.05 to 0.10mm) from edges to center, steel processors find great advantages in using small ultrasonic gauges.

Equipment: Selection of instrumentation depends on the accuracy that is required. The best accuracy can be achieved with the Model 35DL with a 20 MHz (M208) or 10 MHz (M202) delay line transducer. In general, the calibrated accuracy with the Model 35DL combined with a M116 contact transducer is ±0.001 inch (±0.01mm). In the High Resolution Mode this gauge is capable of approaching a calibrated accuracy of ±0.0003 inch (±0.008mm) or better if thickness measurements are taken with delay line transducers under ideal circumstances.
Continuous on-line thickness gaging can also be applied to coiled steel, using immersion type transducers. Contact us for details.

Products used for this application

35 Series
General purpose, lightweight Panametrics-NDT gauges feature optional live Waveform and Adjust Mode. 35DL and 35DL-HP have alphanumeric data logger.

25DL PLUS
General purpose Panametrics-NDT gauge features large LCD with live Waveform and sophisticated alphanumeric data logger.

37DL PLUS
Advanced Panametrics-NDT corrosion gauge with large A-scan display and sophisticated alphanumeric data logger. Features include Thru-Coat, Echo-to-Echo, B-scan acquisition, Emat, and optional Oxide/Scale measurement.