© 2017 Proceq SA
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© 2017 Proceq SA
2.3 The RockSchmidt Display
Single shot Statistics
Review
Conv. Curve
Units
Correction factor
A typical display after an impact shows:
A pseudo-analogue scale mimicking the mechanical drag pointer.
The actual rebound value with a two and a half digit number.
A counter displaying the actual number of valid impacts in a series of measurements.
If there is a battery or low impact energy alert (see chapter 8), it is displayed between the unit symbol
“R” and the rebound value.
2.4 Philosophy of the User-Interface
These simple actions are all that is required to navigate around the menu, set up the RockSchmidt,
perform measurements and review results and settings.
TILT
Tilting means that you raise the left side (plunger side) of the device to scroll to the
icons to the left of the “centred” icon or you raise the right side of the device (SELECT
button side) to scroll to the icons to the right of the “centred” icon.
ROLL
Rolling means that the device remains horizontal, but the display is rolled away from
you or towards you.
SELECT
Press the SELECT button.
TIP
Depress the plunger a short distance, but not enough to trigger it.
IMPACT
Depress the plunger until it triggers.
2.5 Sample Preparation
When performing rebound measurements on core samples, both ASTM and ISRM recommend the
use of a heavy specimen holder to prevent damage to the cores on impact. Ideally it should have
a semi-circular groove with the same diameter as the core, but it may also be a V-shaped groove.
Please refer to the guidelines listed in chapter 2.1 for more details of both specimen preparation and
suitable specimen holders.
When carrying out field testing it may be necessary to smooth the test surface using the grinding
stone provide. Please note however, that this may affect the test result. Further information about
this is contained in a research paper of the University of Oxford via the Proceq website “The use of
the Schmidt Hammer and Equotip for rock hardness assessment in geomorphology and heritage
science: a comparative analysis”.
2.6 Correct use of the Hammer
Perform a few test impacts with the RockSchmidt before taking any measurements which you are
going to evaluate. The single shot mode is useful for this purpose. Perform a consistency check on
the test anvil.
The number of test impacts required for a valid rebound
number is defined in the guidelines. Unless you are using
the weathering grade mode, this will typically be at least 10
impacts. The individual impacts should be separated by at
least the width of the plunger. Ensure that the hammer is per-
pendicular to the test surface. Push the hammer against the
surface at moderate speed until the impact is triggered.
NOTE! The plunger generates a recoil when it deploys. Always hold the RockSchmidt
hammer in both hands, perpendicular to the test surface, before you trigger the impact!
