Presence Detection Crosses Industry Borders
技术分类:机器与离散传感器 作者:Dick Johnson 发表时间:2005-12-05
interesting changes from the previous survey (see accompanying graph on communication protocols). Although the lineup stayed essentially the same over the three-year time period, there were significant gains in the other category. Mentioned most often is Modbus Plus.

Why buy?

No matter which technology fits the application, those who buy proximity sensors provided a litany of reasons for specifying them (see accompanying graph on buying characteristics). Characteristics termed important remain

ed essentially the same from survey to survey, except for automatic sensitivity adjustment and self-teach feature which appeared for the first time in 2005. In the current report, the self-teach feature ranked fourth while automatic sensitivity adjustment came in seventh.

As with most technologies, new features almost always increase adaptability to the industries the devices target. Proximity sensors are no exception. Today's electronic capabilities have made set-up and, in some cases, flexibility of these devices much easier for those who specify and apply them. As the devices become more sophisticated and adaptable, control engineers will find more places to use them.

Proximity sensor products

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Small-package proximity sensors

Line of proximity sensors includes inductive, capacitive, ultrasonic, and analog output types in a variety of sizes and with short-circuit protection. Standard and double/triple sensing distances vary by model. Small-package sensors are suited for applications with limited mount space. Ultrasonic 18- and 30-mm products are high resolution with dc or analog output. All ultrasonic dc models have an LED indicator and can be purchased with adjustable sensitivity. Four models in the analog series feature voltage or current output, metal housing, and axial or quick-disconnects. AutomationDirect