Cygnus twin crystal (dual element) probes are for use with the gauge in Single-Echo or Echo-Echo modes.
The probe face is divided into two: one semi-circle transmits the ultrasound energy and the other receives it back.
They have a hard wear face which will eventually wear down. The gauge will automatically “Zero” the probe to compensate for wear (until there is excessive wear when the probe should be replaced). The gauge will indicate when the probe needs changing with a warning message.
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.
The T5B twin crystal 5 MHz 8 mm probe is recommended for the majority of applications in Single-Echo and Echo-Echo modes.