Proceq N / L - Measurement; Measuring Principle; Measuring Procedure

4 Measurement © 2017 Proceq SA
2 Measurement
2.1 Measuring Principle
The device measures the rebound value R. There is a
specific relationship between this value and the hardness
and strength of the concrete.
The following factors must be taken into account when
ascertaining rebound values R:
- Impact direction: horizontal, vertically upwards or
downwards
- Age of the concrete
- Size and shape of the comparison sample ( cube,
cylinder )
Models N and NR can be used for testing:
- Concrete items 100 mm or more in thickness
- Concrete with a maximum particle size ≤ 32 mm
Models L and LR can be used for testing:
- Items with small dimensions ( e.g. thin - walled items
with a thickness from 50 to 100 mm )
If necessary, clamp the items to be tested
prior to measurement in order to prevent
the material deflecting.
- Items made from artificial stone which are sensitive to
impacts
Preferably perform measurements at
temperatures between 10°C and 50°C only.
2.2 Measuring Procedure
The items ( in brackets ) are illustrated in Fig. 2.4 on
page 5. Perform a few test impacts with the concrete
test hammer on a smooth, hard surface before taking
any measurements which you are going to evaluate.
• Use the grindstone to
smoothen the test surface.
Fig. 2.1 Preparing the test surface
Warning!
The impact plunger (1) generates a recoil
when it deploys. Always hold the concrete test
hammer in both hands!
• Position the concrete test
hammer perpendicular to the
test surface.
• Deploy the impact plunger
(1) by pushing the concrete
test hammer towards the test
surface until the push-button
springs out.
Fig. 2.2 Deploying the impact plunger (1) (model NR)