Taber 710, Operating Instructions Manual

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tion such that the scratch pin does not contact
the specimen during testing.
Individual weights of varying loads mount to the
top of each spline-shaft finger to exert a standard
force on the surface of the test material. The
standard 9-piece weight set includes loads that
range from 2N to 20N. Optional weights are
available to test up to 25N.
After lowering the scratch tips onto the specimen
surface, compressed air drives the platform
under the scratch tips to generate the damage on
the specimen surface.
Interchangeable scratch tips include a precision
tungsten carbide ball mounted to the contact end.
The tips are 1.0mm diameter hemisphere for
scratch testing and 7.0mm diameter hemisphere
for mar testing. An optional holder permits testing
with a conical diamond scratch tool.
The distance between the bottom of the gantry
and specimen table permits testing of flat speci-
mens up to 22mm in thickness. Or, the 'free-float-
ing' feature of the spline-shaft fingers enables you
to evaluate slightly contoured specimens provided
they are rigid or adequately supported. A spring-
loaded specimen holder is standard and can be
mounted to the end or side of the moveable plat-
form. For narrow and odd shaped parts,
adjustable hold-down clamps are available.
INSTRUMENT SET-UP
Remove all contents from the shipping container
and verify that you have all the components.
1. Set the instrument on a flat, level surface.
Four suction cup feet will secure the instru-
ment to the surface.
2. Install the appropriate tips (scratch or mar)
into the end of each spline-shaft finger. Do
not over-tighten.
3. Insert the spline-shaft fingers into the guide
bearings, by matching the pattern on the shaft
and bearing. Each bearing has been pre-
adjusted at the factory. If a shaft DOES NOT
slide easily through the bearings, see MAINTE-
NANCE - Spline Shaft Finger Adjustment.
INTRODUCTION
The Taber ® Multi-Finger Scratch /Mar Tester is
used to measure the relative resistance or sus-
ceptibility of a material surface to scratching,
marring, gouging, scraping and other similar
physical damage not classified as ordinary wear.
Useful in quality control, materials development
and product development, applications for this
instrument are diverse. They include plastics;
rigid organic materials; paints and coatings; soft
metals; linoleum, plus many others. The most
common usage has been in the automotive
industry, including smooth or grained plastics
used in ornamentation or trim.
PRODUCT DESCRIPTION
The design of the Multi-Finger Scratch / Mar
Tester is based on the five-finger (five-arm)
scratching device described in popular automo-
tive test methods.
The instrument includes a pneumatically driven,
moveable platform to which the test sample is
mounted. The platform moves in a linear fashion
and is operated by a control knob, for one or mul-
tiple pass testing. An electronic timer displays
the rate of speed, which is controlled by reducing
or increasing air pressure.
A gantry supports five independent spline-shaft
fingers, which provide a constant, vertical load on
interchangeable scratch tips (1.0mm or 7.0mm
diameter hemisphere). Offering a stable platform
to ensure the rigidity for the scratch tips, the
gantry system includes a handle to raise and
lower the spline-shaft fingers. In addition, five
support rests are incorporated to allow one or
more fingers to be moved to an upright, rest posi-
2 710 Operating Instructions ver 1.1
Mar Tip Scratch Tip