Details of the range of test heads are shown in the summary table below.

    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 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 utililised reliably over many years in an industrial environment.