Single Crystal Probes
Cygnus single crystal probes are for use with the gauge in Multiple-Echo mode to read through and ignore coatings. The S2C single crystal 2.25 MHz 13 mm probe is recommended for the majority of applications and can be used to read through coatings up to 20 mm thick with the gauge in Deep Coat mode.
Twin Crystal Probes
Cygnus twin crystal (dual element) probes are for use with the gauge in Single-Echo or Echo-Echo modes. In Echo-Echo mode, up to 1 mm of coating can be read through and ignored. Single-Echo mode can only be used on bare surfaces or where coatings have been removed.