Nitto CTS-02V4, Руководство пользователя

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3.2 Calculation from Waveform
The waveform of impact force is measured by the accelerometer built-in to CTS-02V4. Fig.
3.2-1 shows the waveform of impact force when hammering the concrete. The acceleration
generated by impact of hammer on the surface of the concrete is actually the decelerated
acceleration. In other words, as shown in Equation (3.6), the impact velocity is given by time
integration until the acceleration reaches the maximum and the maximum impact force can
be computed by multiplying the mass of hammer by the maximum acceleration based on the
law of inertia,.
 
 













3
2
2
1
max
max
max max
T
T
R
T
T
A
dt t A V
dt t A V
MA F
(3.6)
Here,
A
is the acceleration and
T
2
is the time that acceleration reaches the maximum.
Fig. 3.2-1 Waveform
In the actual concrete, the time until the impact force becomes the maximum is the process
that the hammer is pushing onto the concrete surface and the elastic deformation is resulting
(active phase). On the other hand, the time after the impact force reaches the maximum is
the process that the hammer is pushed back by recovering the elastic deformation of the
concrete surface (reactive phase). CTS-02V4 focuses on the reactive phase and used the
following Equation (3.7) as an index. Here, number of a power of velocity can be corrected
according the impact velocity.