Scratch Hardness Tester
LINEARTESTER Model 249

Purpose and Application

The optimised scratch hardness tester LINEARTESTER 249 is intended, in addition to its original purpose of application, i.e. to establish the ability of a surfaces to resist damage by scratching, also for several other tests:
– Scribe/Scratch tests
– To and fro-cycle abrasion tests
– Crockmeter tests
– MEK tests, tests determining the resistance against
solvents in general or wipe test, respectively.

Principle of the Test

The test panel is fixed onto a mobile slide by means of clamping rails.
Above this slide and held on two metal pillars is a reciprocating beam
bedded in a free-moving manner and carrying the adequate test tool
as well as a weight. The required scratching force in the range of
(0.5 to 20)N is set by moving the weight along the reciprocating beam,
making use of a setting scale (an additional load weight of (1 to 40)N
is optionally available). The testing machine is equipped with a
4-position height adjustable load arm device with standard height of
about 10 mm (+20/+40/+60 mm). To use the vertical adjustment,
a set of guide plate high level adapters is also required
(Order No. 02101.01.32).
To start a scratch/scribe test, the test tool is lowered onto the
specimen when moving forward initiating the scratching process
immediately. The optionally used guide plate lifts the tool up, when
the slide with the sample plate moves back. The test panel can be
moved sideways so that a series of scratches can be carried out side
by side with different force settings. Due to a ruler integrated in the
slide plate, an uniform distance between the scratches can be achieved
very easily.
When testing insulating coatings on conducting substrates, an electric
recognition of the through-scratching offers an additional security for
setting the scratching force. For abrasion tests, crockmeter tests,
MEK or wipe tests the test movement is carried out with the tool
lowered onto the specimen, in preset cycles to and fro. For this, the
guide plate has to be removed from the slide plate. There are three
fixed as well as one freely programmable test speeds available.
In addition to the fixed stroke length of 60 mm, the
LINEARTESTER can be equipped optionally with variable stroke
lengths (five additional stroke lengths of 35 mm, 50 mm, 65 mm,
80 mm and 95 mm).

Accessories

Various test tips and other accessories are available. Please download
the leaflet for more information.

Please see leaflet for more info.