© 2017 Proceq SA 13
12 © 2017 Proceq SA
3.5 Checking the Current Settings
The current settings will be displayed when you TIP (see chapter 2.4) the plunger. The display format
is shown below.
Unit Curve
Statistics Correction
4. Applications
Rebound hammers have historically been used for many rock testing applications. Some examples
are:
• Geomorphological applications which investigate the bulk hardness properties of a rock
outcrop.
• Prediction of weathering grades
• Correlation to Unconfined (or Uniaxial) Compressive Strength (UCS)
• Correlation to Young’s Modulus
• Prediction of penetration rates for tunnel boring machines and rotary drum cutters.
• Testing on cores and blocks.
Further information, application notes and a list of reference papers may be found on the Proceq
website.
5. Operating the Instrument
5.1 Single Shot Mode
It is recommended to perform a few impacts prior to obtaining the rebound number to check the
operation of the hammer. Single shot mode is ideal for this. In this mode the results are not saved.
Select single shot mode.
Confirm or cancel the action.
5.2 Measurement Series
The number of impacts required for a valid rebound number depends on the statistics method
selected.
Having selected any optional settings, simply perform an im-
pact to begin.
Impact No. 1.
Between impacts, move to the next location. Unless you are
in weathering grade mode, never impact on the same loca-
tion twice.
Impact No. 20. The series is complete indicated by the colour
reversal on the impact counter.
Press “Select” button to close the series.
Confirm or cancel the action
Rebound value calculated according to statistics method
selected, standard deviation, range and number of impacts.
TILT for UCS estimate defined by the optional settings.
When in ISRM statistics mode only, TILT again for histogram
display.
5.3 Measurement Series – Weathering Grade
This method differs from the others in that only two impacts are performed, both on the same loca-
tion. Typically the second rebound value is higher than the first due to compaction. The difference
can be correlated to weathering grades, (e. g. I – Unweathered, II – Slightly weathered, III – Moder-
ately weathered, IV – Highly weathered, V – Completely weathered, VI – Residual soil.)
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