Self-contained pipeline inspecting system

Claim 1

A PROBE FOR THE INTERNAL INSPECTION OF TUBULAR MEMBERS COMPRISING: AN EXCITER COIL AND A PICKUP COIL, SAID COILS BEING SPACED A DISTANCE SUFFICIENT TO CAUSE THE VOLTAGE INDUCED IN SAID PICKUP COIL AS A RESULT OF A VOLTAGE APPLIED TO SAID EXCITER COIL TO VARY EXPONENTIALLY WITH THE THICKNESS OF THE WALL OF SAID TUBULAR MEMBER; A BATTERYOPERATED ALTERNATING CURRENT POWER SUPPLY COUPLED TO SAID EXCITER COIL; A TRIGGER CIRCUIT COUPLED TO SAID PICKUP COIL AND DISPOSED TO TRIGGER AT A PREDETERMINED POINT IN THE CYCLE OF THE SIGNAL INDUCED IN SAID PICKUP COIL; SAID TRIGGER CIRCUIT BEING COUPLED TO A STOBOSCOPE CIRCUIT TO FLASH A NEON LIGHT WHENEVER SAID TRIGGER CIRCUIT TRIGGERS; A TUBULAR ELEMENT DISPOSED TO BE ROTATED BY A SYNCHRONOUS MOTOR COUPLED TO SAID POWER SUPPLY, THE EDGE OF SAID TUBULAR ELEMENT HAVING A HELICAL SHAPE, THE AXIS OF THE HELIX BEING COAXIAL WITH THE AXIS OF THE TUBULAR ELEMENT, SAID NEON LIGHT BEING DISPOSED WITHIN SAID TUBULAR ELEMENT; A LIGHT SENSITIVE RECORDING MEDIUM DISPOSED TO BE MOVED PAST SAID TUBULAR ELEMENT; A SCANNING SLOT DISPOSED BETWEEN SAID TUBULAR ELEMENT, AND SAID RECORDING MEDIUM TO MASK ALL OF SAID RECORDING MEDIUM EXCEPT THE PORTION ALIGNED WITH SAID SLOT.