| 摘要 |
For the purpose of nondestructive testing of tubes, use can be made of probes having an electric motor (30) for driving a rotating test head (1), in which probes a device for the electrical detection of the angular position of the test head (1) is provided, so that defects can be located as accurately as possible. This device comprises a rotor (100) which is rigidly and directly connected to the test head (1) and consists of two parts (101, 102) of different electrical conductivity, of which one part extends in the form of a narrow strip (102) along the rotor circumference. The rotor (100) is assigned two brushes (103, 104) which conduct, over the rotor (100), a current differing in accordance with the conductivity of the strip (102). A plurality of strips (102) which can be distinguished electrically can advantageously be distributed over the rotor (102) for the purpose of precise measurement of angular position. <IMAGE>
|
