Cygnus - Single Crystal Ultrasonic Probes
Cygnus single crystal probes are for use with the gauge in Multiple-Echo mode to read through and ignore coatings. These have one piezo-ceramic crystal. This crystal both sends and receives the ultrasound energy. The S2C single crystal 2.25 MHz 13 mm (0.51 in) probe is recommended for the majority of applications and can be used to read through coatings up to 20 mm (0.79 in) thick with the gauge in Deep Coat mode.
All Cygnus probes have a protective membrane fitted in front of the probe face to protect it from damage during use on rough corroded surfaces. A thin film of membrane couplant sits between the membrane and the probe face to allow the ultrasound to pass through. The membrane also helps the probe face "mould” to uneven corroded surfaces aiding measurement.
The performance of the probe depends on the condition of the membrane and how well it has been fitted. Cygnus recommends membranes are replaced frequently as a precaution or at the first sign of any scoring, tearing or damage.
Membranes are available in two materials, the standard Polyurethane membrane is suitable for surface temperatures up to 75°C (167°F), the Teflon membrane is suitable for surface temperatures up to 150°C (302°F) with a maximum contact time of 5 seconds.