Patent ID: 6300759
Filing Date: 2001-10-09
Classification: G01N

Abstract:
A test device for suppressing signals when inspecting a prestressed construction element having a prestressing reinforcement and a transverse stirrup, comprising:a testing head (15) for magnetizing the construction element (27) over a predetermined measurement section (21) in two successive magnetization operations by switching a testing head (15) in opposite direction of each other for opposite polarities with opposite polarities;a magnetization device (17) disposed on said testing head for generating a magnetic field around the construction element, said magnetizing device being movable between a starting point (23) and an end point (25) of a range of measurement, said magnetic field comprising an axial field component (H0x) which magnetizes the prestressing reinforcement and a vertical field component (H0y) which magnetizes the transverse stirrups (7);a controller (33) attached to said testing head for controlling the magnetization, wherein said controller switches off the magnetization device (17) at said starting point (23) and at the end point (25); anda signal processing device (35) connected to said controller (33) for performing a residual field measurement and storing available residual field signals (R1, R2) of said vertical field component after said magnetizing device is switched off, wherein said controller mathematically superimposes said residual field signals (R1, R2) stored after the magnetizing process.