Details of the range of test heads are shown in the
summary table. The test heads URP50 and URP100, which
cover the smaller diameters,
have adjustable angle transducers housed in annular chambers. In
operation, the annular chamber is maintained full of water and the tube
passes through close tolerance inlet and outlet guides. The URP200, URP350
,
URP425
and URP500 utilize the contact shoe principle which provides
an advantage
over the annular chambers in that much larger tube off-centre conditions
can be tolerated (typically 6mm) and with a special probe shoe lift
mechanism, most tube end conditions can be accommodated. these test heads
can be used in on-line situations testing tubes/bars with un-cut ends
straight from the production mill. All of the test heads utilize
hydrostatic bearings which offer high load carrying characteristics and
virtually no bearing wear. Rotary heads, of this type, have been utililized reliably over many years in an industrial environment.