Cygnus 3 - Probe Selection and Specifications

M4-CYG3-M-ENG_Iss2.doc
Cygnus 3 Operating Manual
25
Membrane Temperatures
The standard polyurethane membranes are suitable for measuring
surfaces with temperatures up to 75°C.
For measuring on higher surface temperatures Teflon membranes
are available, they are suitable for temperatures up to 150°C. See
accessories on page 121.
When measuring hot surfaces reduce the probe contact time
to a minimum to avoid damaging the probe face and crystal.
Probe Selection & Specifications
Crystal
Diameter
Frequency
Measurement
Range
Application
13 mm
½ inch
2¼ MHz
3.0 – 250 mm
1
0.12 – 10 inch
This is the standard probe
– suitable for most
applications.
13 mm
½ inch
3½ MHz
2.0 – 150 mm
0.08 – 6 inch
Suitable for measurement on
thinner sections where
surfaces are relatively rough
6 mm
¼ inch
5 MHz
1.0 – 50 mm
0.04 – 2 inch
The higher frequency and
narrower beam makes this
Probe ideal for measuring
small-bore tubing, thin section
plate and other areas where
access is limited.
13 mm
½ inch
5 MHz
1.0 – 50 mm
0.04 – 2 inch
Ideal for thin sections without
heavy corrosion.
Lower frequency probes offer better penetration on heavy
corrosion/coatings.
Probe Frequency Identification
The frequency of Cygnus probes is indicated by colour;
Red = 2.25 MHz
Orange = 3.5 MHz
Black = 5.0 MHz
1
To measure thicknesses on tall thin cylinders or columns the height-width ratio should be no
less than 1.0:0.6 (Height:Width) otherwise side reflections prevent measurement.