E-Meter
MK II™
For the determination
of the resonant
frequency of materials.
Applications
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Conforms to ASTM C-215 and C-666.
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The only method of calculating
the following material parameters non destructively:
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Available for specimen sizes up to
6 inches (150mm) cross section dimension and from 1.75 inches (45mm) to
28 inches (700mm) in length.
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Automatic identification of the
resonance frequency. Large easy to view display for data analysis of
time domain and frequency spectrum signals.
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Data can be stored and uploaded to
a PC for further analysis and inclusion in reports.
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Fast and easy to use system.
Principle
The principle used in the E-Meter Mk II™ is
based upon the
determination of the fundamental resonant frequency of vibration of a
specimen generated by an impact and sensed by an accelerometer. The
frequency spectrum is computed and displayed by the meter.
System
The E-Meter™ MK II has an automatic feature
that computes the
maximum amplitude, which eliminates
cumbersome frequency scanning. Frequencies are automatically shown in
the display and a cursor allows the user to move along the frequency
spectrum. Also the time domain signal and the frequency spectrum can be
stored and uploaded to a PC for further analysis and inclusion in
reports.
Resonance
Frequency
The E-Meter™
MK II performs a Fast Fourier Transform that allows the identification
of the resonance frequency in the Frequency Spectrum.
Durability of Concrete
The determination of flexural resonance is
very important when
studying the degradation of concrete under accelerated freezing and
thawing cycles and aggressive environments on concrete specimens.
The
advantage of resonance methods are:
1. Tests
can be repeated over a very long period on the same
specimen; the number of test specimens required is therefore greatly
reduced.
2. The
results obtained with the resonance method on the same
specimen are more reproducible than those obtained with destructive
tests and groups of specimens.
For the determination of
the resonant frequency of
materials,
the E-Meter Mk II™ measures the resonant
frequencies of the three different mode
s of
vibration Longitudinal, Transverse (Flexural) and
Torsional.
From
these the following
material characteristics can be calculated
Young's
Modulus of Elasticity
,
Modulus
of Rigidity and
Poisson™ Ratio.
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Frequency range:
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from 10 Hz to 40 kHz
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Sampling frequency:
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10, 20, 40 or 80 kHz
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Frequency resolution:
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from 4.9 to 78.1 Hz
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Record length
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1024 or 2048 points
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Output bias level:
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9.2 V
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Accelerometer sensitivity:
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9.60 mV/g (0.979 mV/m/s2)
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Battery:
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12 Volt. 4-10 hours - continuous use
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Display:
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320 by 240; backlit for daylight use
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Storage:
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200 plus readings
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Software:
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Windows compatible 9x/me 32MB Ram
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Impactors:
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Set of 6 hardened steel balls.
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Operating Temperature Range:
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0°C to 40°C
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