用傳感器跟蹤工業(yè)過(guò)程

　　工業(yè)過(guò)程的成功在很大程度上是建立在穩(wěn)定、可重復(fù)的條件下進(jìn)行的。這有助于減少過(guò)程中的可變性，提高創(chuàng)建一致輸出的機(jī)會(huì)，并且使故障排除問(wèn)題更加容易。

　　傳感器可用于建立測(cè)量、反饋和控制系統(tǒng)，以穩(wěn)定工業(yè)過(guò)程的操作條件。但是你衡量什么呢？我們將研究一些與工業(yè)過(guò)程控制相關(guān)的基本傳感器類(lèi)型，它們測(cè)量溫度、壓力、濕度、液位、氣體濃度和質(zhì)量流量等因素。了解什么是傳感器，它們是如何工作的，以及它們的功能和局限性，有助于設(shè)計(jì)者創(chuàng)建監(jiān)控系統(tǒng)，提供必要的精確信息，以確保工業(yè)過(guò)程的穩(wěn)定性和可重復(fù)性。

　　Temperature

　　Tracking temperature is one of the most basic elements of process control. Although we are used to thermistors and temperature probes， other approaches are emerging to make it easier to gather multiple temperature readings from large installations.

　　Take Maxim’s DS18S20， a ‘1-wire’ digital thermometer， which only needs a single data line to communicate with a host controller. The part is available in a three-leaded TO-92 package， on which two of the leads are dedicated to power and ground and the third is the data output， and in an 8-pin Small Outline package with five unconnected leads. The thermometer can even draw its power from the data line， removing the need for a separate supply and simplifying installation.