Laser Type Extensometers0 pages

Bulletin
TD-2005

Laser Type Extensometers
The Tinius Olsen model 500LC
non-contacting extensometer is
designed to measure the extension of
medium to high elongation materials,
typically elastomers. Since there is no
contact of this extensometer with the
sample, the 500LC is ideal for also
measuring the elongation of fragile
samples where such contact could
induce a premature sample break.
The model 500LC uses a low
power helium neon laser with
precision optical components and a
dedicated 16 bit processor. The laser
projects a visible red scanning beam
that is directed at two reflective
targets attached to the specimen.
An additional benefit of using laser
technology is its ability to scan the
test specimen through the glass
viewing window of an environmental
test chamber. Elongation characteristics can then be evaluated from
–70° C to 300° C.
Preparation of the test specimen is
quick and easy. A punch is supplied
to cut narrow strips of adhesive
reflective tape. The gauge length is
defined by attaching these two
reflective strips to the sample. Any
gauge length can be used and this is
accurately measured by the laser at
the start of the test.

Fig. 1. Model 500LC scanning laser extensometer.

500LC

MODEL
RANGE OF SCAN

in
mm

ACCURACY

up to 23.6
up to 600
1% of 25 mm gauge length, BS5214 grade D

RESOLUTION

in
mm

4.72 e-4 with filtering
0.012 with filtering

GAUGE LENGTH

in
mm

0.39 to full scan
10 to full scan

OPTICAL SCAN RATE scans per second

320

OPTICAL SCAN ANGLE degrees

90

DIMENSIONS
HxWxD

in
mm

WEIGHT

lb
kg

32 x 14 x 14
330 x 111 x 180
55
7

6.33 mm 0.5 mW (He-Ne) laser conforms to BSEN60825.1992 Class 2