The German ERICHSEN426 scratch meter is used to make standard scratches on samples in corrosion tests. The diameter of the tungsten carbide tip is 0.5mm. The 426 scratch meter is also called a scratch pen.
Testing principle of German ERICHSEN426 scratch meter
Used to produce special scratches on the protective coating surface by scratching the test specimen with a test needle at the beginning of the corrosion test and at regular intervals. These scratches are made horizontally one above the other, with the first at the bottom of the short side of the sample. In this way the progression of the rust can be easily studied.
The Ï0.5mm (Ï0.020â) spherical tungsten scratching needle is firmly installed on the oxidized duralumin pen-shaped handle. The special comfortable design ensures stable use during scratching operations.
The spherical test points have been subjected to the following durability tests:
The surface of a piece of Ï100mm (Ï4") round steel on a lathe was scratched by a scratching needle at a speed of 20cm/s (8") and a pressure of 50 N (11 Lbs). After running for 18000cm (600ft) , there will be no damage to the spherical test point. This means it can produce 2,000 scratches up to 90 mm (31/2â) long without damage.