Inspection of header tube holes

Apparatus for scanning header tube holes includes a probe assembly (30) designed to engage the surface of a header encircling a header tube hole. The probe assembly includes a spring mounted sensor (31, 32) which is preferably an eddy current probe. A mechanism (40) is provided for supporting and positioning the probe assembly (30). The mechanism (40) is provided with resilient rings (43, 47) which, in operation, engage the tube stub. A drive device (50) is provided for imparting axial and circumferential movement to the probe (31, 32) relative to the surface of the hole which is to be inspected.