Ultrasonic probes for high temperature immersion measurements

Abstract

Ultrasonic probes for high temperature measurements in immersion are presented. These probes consist of piezoelectric transducers and buffer rods, and may be operated in the pulse echo mode. The probes can operate to temperatures as high as 215 • C without requiring a cooling system. For imaging purposes, one end of the clad buffer rod is machined into a semi-spherical concave shape, of which the purpose is to focus the ultrasound. The operating frequency is between 5 and 9 MHz. Ultrasonic images, produced using a mechanical raster scan with the probes fully immersed in silicone oil at elevated temperatures, are presented. The importance of the signal-to-noise ratio in the pulse-echo measurement is discussed.

High-temperature (>500°c) wall thickness monitoring using dry-coupled ultrasonic waveguide transducers

“…Jen and co-workers [23], [24], [25], [26] have tried to limit the number of modes traveling in a thin bar by adding an attenuative cladding on the outside of the bar, the bar usually being tapered. This is essentially an attempt to remove the effects of the waveguide boundaries by reducing the amplitude of reflections from the surface.…”

High temperature ultrasonic immersion measurements using a BS-PT based piezoelectric transducer without a delay line

“…Moreover, the front wall echo is affected by the gas bubbles adhering to the nickel faceplate of the transducer. Hence, silicon oil with smoke point greater than 200C was selected [62][63] for the evaluation of high temperature immersion ultrasonic transducer. The experimental arrangement and procedure is same as explained in section Fig.…”

Under-Sodium Viewing: A Review of Ultrasonic Imaging Technology for Liquid Metal Fast Reactors

“…They have been successfully applied to ultrasonic imaging under molten metals (Ihara et al 2000;Rehman et al 2001;Ono et al 2002b;Ono et al 2003Ono et al , 2004Ono et al 2006). The clad buffer rod consists of a mild steel core with a double-tapered shape, a thermal sprayed stainless steel inner cladding, and bronze outer cladding.…”

“…Tests on the ANL ultrasonic waveguide system were conducted using the LMFBR (liquid metal fast breeder reactor) simulation heat transfer loop (Lynnworth et al 2005) on the ANL campus. The waveguide approach is also used for imaging and inclusion detection in metal smelters where liquid metal temperatures can approach 1000°C (Ihara et al 2000;Rehman et al 2001;Ono et al 2002a). In lightweight metal processing (e.g., aluminum and magnesium) quality is critically associated with inclusions within the molten metal during manufacturing steps.…”