User experience assessment of new augmented reality (AR) technology is an increasingly important area of research, including industrial applications. In our domain, many services field technicians have traditionally relied on stand alone tools with restricted connectivity and information visualization capabilities for on-site diagnostics and maintenance. With new hand-held and wearable AR technology and recent developments in cloud-based computing, new services can be delivered so that they are more interactive and more connected, with a goal to ultimately improve the efficiency and productivity of the technician. It is fundamental for acceptance that this technology enables a high quality of user experience, and a user-centered design framework is necessary for the testing and evaluation of these new technologies. This paper presents a testbed that we are building at United Technologies Research Center that leverages user-centered design framework for developing and deploying AR applications both for hand held devices as well as wearable AR glasses. We present two test cases from our testbed: (a) a hand-held based AR application for active diagnostics in building HVAC systems; (b) an interactive AR application for aircraft engine maintenance based on wearable see-through AR glasses.