Smart sensors are still a little on the leading edge, but many manufacturers are beginning to exploit their functions.
A recent survey of Automation World subscribers and Web site visitors (www.automationworld.com) found that 86 manufacturers are currently using smart sensors. For the purposes of this survey, smart sensors were broadly defined as sensors with embedded intelligence or diagnostics. This was 71 percent of respondents.
Of the types of smart sensors that manufacturers used, most were process sensors/transmitters. These include temperature (67 percent of those responding), as well as pressure and flow (59 percent each). Discrete sensors, photoelectric and proximity, ranked next, with about 49 percent of respondents using them. Position sensors and vision systems followed these at about 36 percent each. Perhaps indicative of progress that vision suppliers have made in ease-of-use, the number of manufacturers using vision sensors or systems (36 percent) was not all that far behind the number using discrete sensors.
Shutdowns of a manufacturing process or piece of machinery are costly. If a sensor could report its status and perhaps warn operations personnel about impending failure, then the sensor could be replaced at a convenient time, thus avoiding unnecessary expense. Indeed, the most popular reasons for using smart sensors among survey respondents were diagnostics (67 percent of respondents) and troubleshooting (59 percent).
Ethernet has been hyped for several years as a viable industrial network. Evidently, Automation World readers have weighed the evidence and voted for that seemingly ubiquitous network. Nearly as many manufacturers (64 percent) reported using it as the venerable 4-20 mA network (69 percent). DeviceNet was used by 46 percent of the responding manufacturers to rank next.
When asked about using any wireless method for sensor networking, 122 manufacturers responded with 30, or 25 percent, answering “Yes.” This is actually a surprisingly robust positive response that should give wireless vendors heart that they are on the right track.
The survey gages the benefits users can expect from asset management systems. About 17 percent of those responding have documented savings. Of the 85 people who responded as to why they have not adopted asset management software, 41 percent said they needed to evaluate these systems further before making a decision. Interestingly, 28 percent said that they just didn’t believe that their present systems were integrated enough to attempt using another software solution on top of them.