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 (0.04 in) 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 (0.315 in) probe is recommended for the majority of applications in Single-Echo and Echo-Echo modes.

Details of our range of twin crystal probes
Details of our range of twin crystal probes

Probe IDNumberFrequencyFaceSize ConnectorType Range in Steel inSingle-Echo Mode(not through coatings)Range in Steel in
Echo-Echo Mode
(through coatings up to 1 mm (0.04 in))
Typical Application
T5B5.0 MHz8 mm
(0.315 in)
TwinLemo 001.5 – 200 mm
(0.059 – 7.900 in)
4 – 50 mm
(0.160 – 2.000 in)
General purpose
Most metals
T2C2.0 MHz13 mm
(0.51 in)
TwinLemo 002.5 – 250 mm
(0.098 – 10.00 in)
5 – 50 mm
(0.200 – 2.000 in)
Attenuative materials, cast irons and plastics
T7A7.5 MHz5 mm
(0.2 in)
IntegralCable0.8 – 50 mm
(0.031 – 2.000 in)
3 – 25 mm
(0.120 – 1.000 in)
Thin metals and small diameter pipes


Gauge Type
Probe TypeC2+C4+C6+
 Gauge has Twin Lemo 00 Connector
T5BT2C004-0411Twin Lemo 00 to Twin Lemo 00
T7AIntegral Cable

For the DIVE gauge, the probes are fitted with integral cables.

Download Twin crystal probes brochure