© 2017 by Proceq SA
14
© 2017 by Proceq SA
15
5.6. Basic Measurement – Compressive Strength (Pundit Lab
+
only)
Prior to carrying out this measurement, a conversion curve must be created in PunditLink and
uploaded to the instrument. Up to five curves may be stored on the instrument. Select the
appropriate curve and set the desired compressive strength unit. (See chapter 3 “System Set-
tings”.) Carry out a pulse velocity measurement as described above (5.3).
While the measurement is being carried out, or
when the measurement has completed, clicking
on the up or down keys switches between pulse
velocity and compressive strength indication.
SONREB Method
This method for measuring compressive strength combines the ultrasonic measurement with
a rebound hammer measurement.
The format of the curve is: Compressive Strength f
ck
= aV
b
S
c
Where:
a, b and c are constants
V is the ultrasonic pulse velocity in m/s
S is the rebound value.
Many examples of SONREB curves can be found in the literature
In the settings menu (Chapter 3) the rebound value should be entered before carrying out the
measurement. In this case the rebound value entered is saved along with the rest of the mea-
surement data.
A rebound value of 83.1 has been entered here
and saved with the measurement data.
i
Note:
The rebound value may be a Q-value (SilverSchmidt) or an R-value (Origi-
nal Schmidt). This is for the user to define, but it is always displayed in the
review list as “R for rebound value”.
5.7. Compound Measurement – Surface Velocity
Select “Compound Measurements”
Select "Surface Velocity"
Select parameter setting “b”.
Measure and enter the distance “b”
Transducers in first position – Start
“t1” is measured. Stable reading
indicated by a tick
Receiver to 2nd position - Start
“t2” is measured. Stable reading is
indicated by a tick and result screen
is displayed.
The display shows:
- “t1”
- “t2”
- Surface velocity
Save the result or press start to
repeat the measurement.
