The United States spends 16 percent of its gross domestic product (GDP) on health care, more than any other nation. Although that investment has produced medical experts and breakthroughs envied the world over, a great majority of U.S. citizens are unhappy with the end results. When the nonpartisan Commonwealth Fund conducted a poll of U.S. health care consumers last year, 69 percent expressed strong dissatisfaction with the current health care system. In a 2007 survey, the same group found U.S. respondents twice as likely to support a complete overhaul of their system than those from Canada, Germany, the Netherlands, New Zealand, Great Britain, and Australia--all nations that spend half as much GDP as the United States on health care.

Most articles about measuring devices, instruments, or systems describe what they do and how they work. The manufacturers of these systems want readers to know about the innovation and technology that went into them. However, the missing part of such articles is how to use the measuring system to get the information that the user needs to make decisions. This article looks at multisensor metrology from a user’s perspective.

On-machine verification (OMV) is a recent innovation that combines existing technologies to solve more complex measurement problems on machine tools. Many machine tools are equipped with probing systems, and using the probe for simple part setting is an established process. Simple macro-based probing cycles allow the user to measure basic features such as faces, corners, and bosses, and these can be combined to create rudimentary inspection reports. These basic solutions are restricted to simple 2-D measurement because 3-D measurement is just not practical. Although skilled operators can sometimes adapt probing macros to measure along compound angles, this becomes too difficult and too time-consuming for complex, curved surfaces.

OMV solves these problems using graphical 3-D software methods to program the measuring sequences. The programming and reporting tools from inspection software are combined with machine tool post-processor expertise to create a measuring solution for machine tools.

Real-time X-ray inspection systems have been used in quality assurance applications for more than 25 years. In electronics manufacturing, for example, X-ray inspection ensures the registration of drilled holes to internal pads of multilayer printed circuit boards. In electronic assembly applications, X-ray inspection ensures the quality of hidden solder bonds of surface-mounted components such as ball-grid arrays, as seen in figure 1 below.

Now real-time X-ray inspection is becoming an important tool for ensuring the quality of many medical devices. These devices incorporate a diversity of materials, including polymers, rubbers, steel, titanium, ceramics, and glass. Real-time systems employ fluoroscopic imaging devices to display the device’s X-ray image in a video format.