Anatest Kalite Kontrol ve NDT Cihazları

A 1040 MIRA 3DUltrasonic Tomograph

The ultrasonic low-frequency tomograph A1040 POLYGON for concrete inspection was given a new name MIRA for international markets.
The name MIRA originates from two words: a Spanish word “mirar” – to look and an English “mirror” or reflection, which refer to the operation principle of instrument – to look in the concrete, using a ultrasonic pulse-echo testing technique and reflect the internal structure using tomographic SAFT-imaging of results - a handheld item for in-site inspection of objects.
Let the MIRA help you see what’s hidden in the concrete.

Introduction

The low-frequency linear ultrasonic tomograph A1040 POLYGON is a multifunctional focusing array system , applicable for non-destructive testing with low-frequency ultrasound range (20-100 kHz) and tomographic methods of signals processing.

The tomograph A1040 MIRA is applicable for imaging of the internal structure of objects from concrete and reinforced concrete using pulse-echo technique of testing at one-side access to the object in order to search for foreign inclusions, holes, flaws, cracks, honeycombs, positioning of ducts and other inside the material and also to assess the state of reinforcement bars in concrete.

Features:

Real-time Imaging of the internal structure of the obejct for easier understanding of testing results.

Focusing antenna array of 40 elements (DDF-principle) – better resolution and higher sensitivity of the system, at that the focusing in every point of volume is provided.

Automatic calibration on the object from 8 positions:
- Automatic measurement of average ultrasonic velocity in the object
- Compensation of surface SH-wave providing clearer image in near surface area

Tomographic data procession (SAFT-algorythm)

Special features

Dry acoustic contact;
Pulse-echo testing method at one-side access to the object;
Adaptation of antenna array to the rough object surface.

Description of the system

The A1040 MIRA tomograph consists of 10 measuring units, combined into a focusing antenna array, controlling unit and interface unit of PC type, which received and processes signals and controls the operation of the system.

Each measuring unit consists of 4 low-frequency broadband TM1802 transducers with the nominal operation frequency of 50 kHz, sending shear waves using dry point contact. The transducers have wear-resistant ceramic pin, prolonging the lifetime of the transducer even when operating on rough and unprepared surfaces.

Each transducer features an independent spring load, which allows performing testing on uneven surfaces.

As an interface unit the personal computer of laptop type with special software, allowing controlling the system, tomographic process of data received from the antenna array and saving and printing the testing results.

Data acquisition from one position of antenna array:

Data massive received in one position of the array is an accumulation of signal realizations from all the possible pairs of measuring units of antenna array. The received signals are processed in controlling unit and then transmitted to PC, where in a special software are reconstructed to the image of the internal structure of the object. This operation principle provides focusing in every point of the halfspace. The time on data collection, processing and image reconstruction is 3 seconds.


Şekil 1. Bilgi kazanımı	Şekil 2. B, C, D-Scan


Şekil 3	Şekil 4	Şekil 5

Data representation in the software on the display of the PC

Imaging of internal structure;
Data representation as B-Scan, C-Scan, D-Scan, 3D volume image reconstruction;
Localization of defects;
Measurements of signal levels in any point of tomogram;
Threshold and smoothing filtering of tomogram;
Half-tone or color representation of signal levels;
Manual or automatic modes of threshold image processing;
Choice of tomogram on 3D image of reconstructed volume;
Saving of the initial data massive and of synthesized reconstructed images in the memory of the PC
Printout.

Operation modes

CALIBRATION mode

In CALIBRATION mode the system is calibrated on the parameters of the object: ultrasonic velocity and signal amplification. Any testing of object is started with Calibration. Also during the calibration the surface SH-wave is compensated providing the better imaging in close to surface area.

VIEW mode

In this mode the data is reconstructed as B-Scan from one position of the array. It is used for quick estimation of the internal structure of testing object in random positions. The operator places the antenna array in the area subjected to testing and receives the B-Scan image of the structure under the antenna array.

DATA COLLECTION mode

This mode is for data acquisition and automatic saving to the hard disk with all the current parameters, setups and calibration results. Is used for data collection from several positions of antenna arrays (line). The operator can also view the received B-scans in every position. On the display the is only B-scan in current position of the array is available.

REVIEW mode

Review mode is for detailed analysis of testing results, received in DATA COLLECTION mode. The testing results in different scans are represented in the Graphical Results Review window. It can give the results as one section mode - B-scans (similar to VIEW and DATA COLLECTION modes) or as combination of different sections B-, C-, D-scans.