MTS Axial Extensometers - Manual (Page 52)

Installation 52
See your controller manual for information on establishing the
extensometer zero output signal. The electrical output of the
extensometer is adjusted so that zero strain equals zero volts output.
Depending on the extensometer, the zero reference can be accomplished
using the zero pin, stop block, or a special fixture.
• Some extensometers includes a zero pin that can be inserted
into a zero reference hole. This locks the extensometer arms in
the zero reference position. This is useful for specimen
installation.
• Some extensometers have a zero stop built into the arms of the
extensometer. A zero stop works like an overtravel block.
When installing a specimen, pinch the two arms of the
extensometer together. This stops the extensometer’s arms in
the zero position.
• Some extensometers require special fixtures that set the arms
of the extensometer into the proper zero reference position.
How to Mount an Extensometer
Axial extensometers can be installed using quick attachment springs,
extension springs, or elastic bands.
• There are two types of quick attachment springs: a sliding spring
and an anchored spring.
• Extension springs and elastic bands mount the extensometer to a
specimen in the same way.
Prerequisites
The extensometer must be configured with the appropriate attachments
for the specimen and test.
The extensometer must also be calibrated for use. Every range defined
for the extensometer should be calibrated.
Procedure
When installing an axial extensometer on a specimen, the arms of the
extensometer must be in the zero reference position.