А1040 MIRA Low-Frequency Ultrasonic TomographOperation Manual41ACOUSTICCONTROLSYSTEMS2.2.2.1 Preparation of the surface of the tested objectTo prepare the surface of the tested object, please clean the areas, where the device will be installed, remove all dust andsand and the materials disturbing to penetration of low-frequency ultrasonic waves. Any layers other than concrete, such aspolymeric or waterproofing materials or a thick paint coating on physical properties can negatively influence the work of thetomograph.No contact liquid is necessary for the operation of the device.Even and smooth surface of the inspected object gives a better acoustic contact for the device elements with a surface andtherefore improves the quality of the image. Thus, it is necessary to choose whenever possible more even and smooth surfaces.It is possible to work with the roughness of the surface up to 8 mm, however, it is better to make the uneven surface smooth.2.2.2.2 Creating a scanning pattern and treatment of the surface of the tested objectPrior to start the inspection it is necessary to mark the tested object. The pattern of tested object shows where and how toplace the antenna array. Correctly made pattern accelerates the process of the data collection and simplifies the understandingof the inspection results.When performing the local testing it is necessary to mark the places where the device will be placed.When performing the continuous testing a more detailed marking is required. The surface of object should be divided intosections (horizontal and vertical lines) with the constant step (100 mm is the most effective) which is set in the menu. Lines aredrawn on the surface of the testing object with a ruler and chalk.After marking the tested object, it is possible to start the inspection.2.2.2.3 Switching on the deviceThe device is switched ON using the key on the front panel.NOTE: THE DEVICE IS SWITCHED ON WITH A SHORT DELAY. AFTER PRESSING THE KEY THE PROMPT WILL APPEARON THE DISPLAY IN 10 SECONDS. A REPEATED PRESSING OF THE KEY IN THESE 10 SECONDS LEADS TO THESWITCHING OFF.After the device is switched on the green LED on the device antenna is on.2