This manual provides basic instructions for the use of EXFO OTDR series Optical Time Domain Reflectometers, including the setup of the device, measurement of optical cables, analysis of measurement results and generation of reports. This user's manual contains useful information about the instrument's functions and operating procedures and the handling precautions of the AQ7270 Series OTDR. To ensure correct use, please read. 15 EXFO Inc. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form, be it electronically, mechanically, or by any other means such as photocopying, recording or otherwise, without the prior writt eved to be accurate and reliable.