Test appts. which establishes quality of coated or enamelled metal sheet esp. of old car bodies

摘要

The test appts. employs a permanent magnet (8) inside a small housing fixed on one or more pressure sensors. Alternatively the inductance of a laterally screened coil is led as a measurable voltage to an evaluation unit. The respective measurement result is compared with a reference value adjustable across a regulator. At least two rollers are located at the base of the measurement head (1) which is provided with a holder (2). The measurement head is rolled on the metal sheet in the same manner as a doctor listens to the human heart beat. A positive feel of user enables personal choice to be made e.g. when buying secondhand car.