Model 435 S

At first developed from the Mar Tester 435, Model 435 S has been adjusted, in cooperation with a well-known manufacturer of – among others - scaled indication fittings for vehicle cockpits, especially to tests of this product group. When used as an adhesion tester e.g. the coloured coating applied to the dial of a speedometer in the shape of raised numbers, points or scale lines, is tested concerning its adhesion to the substrate, by lateral slipping with a defined “blunt” test body geometry, with a preselected test force.

Design and Function:
The main difference between the Mar Tester 435 and the new Model 435 S is the direction in which the test body is moved. While the test body of Model 435 (a disc with locking facility) is moved relatively fast in longitudinal direction in order to produce a “scar”, the test direction in which the test body of Model 435 S is guided, is rotated by 90°. The part of the test body relevant for the test, corresponds in its shape exactly to that of Model 435 and is basically, for the time being, only available in the version made of steel which is most useful within the scope of products tested up to now. As the diameter of the test head of Model 435 S is considerably smaller compared with the steel disc of Model 435, a central sector of the disc of Model 435 has been chosen as test body for reasons of space saving. The test body is mounted on a bolt and is preloaded by an internal helical spring to a force adjustable from 0 to 20 N. When placing Model 435 S with the two guide wheel perpendicularly onto the surface, the rigidly arrested test tool acts (with the preset force) upon the surface. The test force can be varied – as for Model 435 – by means of 3 exchangeable springs covering three different test ranges.

In principle the Model 435 S is feasible for testing the adhesion of almost all printed scales, numbers, letters and marks "lying" on the scale plates’ surface! When used as a scratch resistance tester for testing surfaces against "blunt" effects, it is recommended for testing surfaces on which the Hardness Test Rod 318 is still too "aggressive" – even using the largest tip diameter of 1 mm available for this purpose.

Method of Operation:
After checking the tight fixing of the test tool at the end of the load transmission bolt, the required force is adjusted on the scale using the locking screw slider. Then the Model 435 S is placed perpendicularly onto the surface to be tested resp. beside the applied raised coating to be tested, and is pressed down so that the guide wheels touch the surface. In this way the preset force acting upon the test tool is fully effective on the test surface. The instrument is now moved into the rolling direction the wheels over the specimen to be tested e.g. against, for example, scale lines. The user selects the speed that is adequate for the product to be tested. When testing e.g. raised inscriptions, the test result is expressed by the test force in Newton (N) at which the adhesion of the coating failed. For scratch resistance tests of surfaces against "blunt" effects the test result is the maximum force in Newton (N) at which the test tool does not leave any trace on the test surface.

Scope of delivery:

• Adhesion and Resistance Tester, Model 435 S
• Test disc made of steel
• 3 force springs
• Case

NEW - ERICHSEN SmartPen - The new generation of mobile scratch hardness testing

For the hardness measurement of surfaces, there are our since many years well-proven hardness test pencils, models 318 and 318 S as well as models 435 and 435 S, already well established across the branches. With these test devices, the degrees of hardness of paint films, plastic coatings, etc. can be determined, named, documented and communicated in numerical values. No matter whether on a flat or curved surface, small or large, the instrument is always ready for use and, because of it’s small size, easy transportable.With the ERICHSEN SmartPen, a modular hardness test pencil with digital test force setting and display (resolution 0.05 N) is now available.