Nondestructive Testing of Moist Cetris-Basic Wood-Cement Chipboards by Using Impedance Spectroscopy

2015 ◽  
Vol 1124 ◽  
pp. 203-208 ◽  
Author(s):  
Miroslav Luňák ◽  
Ivo Kusák
Keyword(s):  
Impedance Spectroscopy ◽  
Water Content ◽  
Impedance Spectrum ◽  
Measuring Method ◽  
Non Destructive Testing ◽  
Inhomogeneous Materials ◽  
Destructive Testing ◽  
Stress Cycle ◽  
Non Destructive ◽  
Method Group

Impedance spectroscopy (IS) is a non-destructive testing (NDT) method ranking in the electrical engineering measuring method group. It outputs data providing information on material electric and dielectric properties. Microscopically inhomogeneous materials are frequently used in the building industry. Unfortunately, the impedance spectroscopy results and their characterization on the basis of this method are not unambiguous. The frequency spectrum behavior of Cetris-basic specimens was studied by means of the NDT impedance spectroscopy method for various water content values. A stress cycle with defined absolute water content values is described. Influences of potential dielectric losses and the predominance of the polarization and conductivity components in various regions of the impedance spectrum are described for various water content values.

Tracing of Concrete Hydration by Means of Impedance Spectroscopy (New Tool for Building Elements Testing)

2012 ◽  
Vol 248 ◽  
pp. 370-378 ◽  
Author(s):  
Ivo Kusak ◽  
Miroslav Lunak ◽  
Pavel Schauer
Keyword(s):  
Impedance Spectroscopy ◽  
Setting Time ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Testing Method ◽  
Specimen Quality ◽  
Concrete Hydration ◽  
Tan Δ ◽  
Non Destructive ◽  
Method Group

Concrete setting and hardening designate the concrete grade. The impedance spectroscopy method, as one of the non-destructive testing method group, was used to characterize concrete specimens and track the changes in the concrete spectrum. Variances in the tan δ (f) and Im Z(f) or Re Z(f) of the specimens under investigation have been observed. The specimen quality has been described by means of the loss type prevailing in the material. The results of this study are expected to provide information about the correlation between the n-factor and the concrete setting time.

Influence of Water Content on Fundamental Frequency of Mortar Sample

2015 ◽  
Vol 1124 ◽  
pp. 273-279 ◽  
Author(s):  
Ladislav Carbol ◽  
Jan Martinek ◽  
Ivo Kusák
Keyword(s):  
Water Content ◽  
Fundamental Frequency ◽  
Non Destructive Testing ◽  
In Situ Testing ◽  
Mortar Sample ◽  
Destructive Testing ◽  
Impact Echo ◽  
Influence Of Water ◽  
Non Destructive

Ultrasonic non-destructive testing methods such as Impact-echo are often conducted under different conditions. Such results might be distorted by ambient temperature or by water content of the tested sample. Tested mortar sample displayed shift of the fundamental frequency by 3.7 %. This article confirms necessity of standardized conditions during ultrasonic testing for both laboratory and in-situ testing.

IMPEDANCE AND MODULUS SPECTROSCOPY OF (Na1/2Bi1/2)1-xCaxTiO3 CERAMICS

2002 ◽  
Vol 16 (31) ◽  
pp. 4755-4766 ◽  
Author(s):  
B. V. BAHUGUNA SARADHI ◽  
K. SRINIVAS ◽  
T. BHIMASANKARAM
Keyword(s):  
Impedance Spectroscopy ◽  
Bismuth Titanate ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Modulus Spectroscopy ◽  
Testing Tool ◽  
Equivalent Circuit Parameters ◽  
Spectroscopy Studies ◽  
Non Destructive ◽  
Impedance And Modulus Spectroscopy

Impedance spectroscopy studies of calcium doped (Ca=0.01, 0.05, 0.1) sodium bismuth titanate (NBT), that is, ( Na 1/2 Bi 1/2)1-x Ca x TiO 3 (NBCT) solid solution are studied as a function of temperature (RT — 575°C) and frequency (100 Hz–1 MHz). The electrical properties and equivalent circuit parameters of Ca doped NBT, and it's bulk and grain boundary effects are studied with impedance spectroscopy as a non-destructive testing tool.

Dielectric Properties of Concrete Specimens after Heat Stress

2013 ◽  
Vol 446-447 ◽  
pp. 1389-1394 ◽  
Author(s):  
Miroslav Lunak ◽  
Ivo Kusak ◽  
Zdenek Chobola
Keyword(s):  
Heat Stress ◽  
Stress Factors ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Testing Method ◽  
Concrete Quality ◽  
Specimen Quality ◽  
Tan Δ ◽  
Non Destructive ◽  
Method Group

Concrete quality depends on various stress factors. The impedance spectroscopy method, as one of the non-destructive testing method group, was used to characterize concrete specimens and track the changes in the concrete spectrum after heat stress. The temperature range was between 0°C and 1200°C. Variances in the tan δ (f) and Im Z(f) or Re Z(f) of the specimens under investigation have been observed. The specimen quality has been described by means of the loss type prevailing in the material. The results of this study are expected to provide information about the correlation between the relative permittivity and changes in the structure for heat stress samples.

Non-destructive testing using electromagnetic impedance spectroscopy

1993 ◽  
Vol 35 (1-4) ◽  
pp. 833-839
Author(s):  
L.A. Williams ◽  
S.E. Faidi ◽  
S.B. Lyon ◽  
R.A. Cottis ◽  
K.R. Baldwin
Keyword(s):  
Impedance Spectroscopy ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Non Destructive

Strain analysis by means of digital shearography: Potential, limitations and demonstration

1998 ◽  
Vol 33 (2) ◽  
pp. 171-182 ◽  
Author(s):  
W Steinchen ◽  
L X Yang ◽  
G Kupfer ◽  
P Mäckel ◽  
F Vössing
Keyword(s):  
Strain Measurement ◽  
Speckle Pattern ◽  
Strain Analysis ◽  
Measuring Method ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Out Of Plane ◽  
Recent Developments ◽  
Plane Displacement ◽  
Non Destructive

Shearography, also called speckle pattern shearing interferometry, is a coherent optical method which measures displacement derivatives directly. It is suited well for localization of strain concentrations and has been used as an industrial tool for non-destructive testing (NDT) in the last few years. However, its application for strain measurement has not been widely adopted in industry, because, in general, shearography can measure only out-of-plane displacement derivatives ∂w/∂x and ∂w/∂y. This paper presents recent developments of shearography for strain measurement. With the support of digital image processing the automatic and quantitative evaluation of the shearogram becomes possible. Not only flexural strains [∂2w/∂x2, ∂2w/∂y2 and ∂2w/(∂y)] but also in-plane strains (∂u/∂x, ∂v/∂y, ∂u/∂y and ∂v/∂x) can be determined by the shearographic measuring method. The potentials and limitations for strain measurement are discussed. Some applications are shown.

Non destructive testing of works of art by terahertz analysis

2013 ◽  
Vol 64 (2) ◽  
pp. 21001 ◽  
Author(s):  
Jean-Luc Bodnar ◽  
Jean-Jacques Metayer ◽  
Kamel Mouhoubi ◽  
Vincent Detalle
Keyword(s):  
Non Destructive Testing ◽  
Destructive Testing ◽  
Works Of Art ◽  
Non Destructive
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