【正文】 所有的復雜的設(shè)備和分析工具是幫助使用者理解檢測對象。一些關(guān)鍵的應(yīng)用包括 : ?產(chǎn)品特征 ?電子產(chǎn)品的熱靠模切削 ?環(huán)境的測試 。前端數(shù)據(jù)采集在很多模型里都能運行，包括 VXI 版 本 ,如 Agilent E1419A 多功能測量和 VXI控制模型，還有專有的卡片升降室。 8前端數(shù)據(jù)采集 前端數(shù)據(jù)采集經(jīng)常做成模塊而且是典型地與 PC機或控制器連接?？? A/ D 轉(zhuǎn)換技術(shù) ,一定的數(shù)據(jù)電子自動記錄儀閱讀的速率比較低，尤其是跟 PC機插件卡片比較。一旦你全部設(shè)定好，數(shù)據(jù)電子自動記錄儀就如同無與倫比的裝置運行。大部分能夠直接地測量若干不同的輸入信號，而不需要額外的信號監(jiān)測器件。它們能夠處理多信號輸入，有時可達120通道。為了測量其他輸入信號，如電壓、溫度和阻力，你也許需要一些外部信號監(jiān)測的器件。 PC 機卡也相對的便宜 ,一部分地，因為他們以來主機 PC 去提供能源、機械附件和使用界面。 5PC機插件卡片 PC 機插件卡片是單板測量系統(tǒng)，它利用 ISA 或 PCI 總線在 PC 機內(nèi)擴大插槽。儀器的背面有一個槽孔接收一張在較多輸入時能多重發(fā)訊的掃描儀卡片，通常是 8 到 10 通道的多路復用器。舉例來說，他們不能夠與另外的裝置輪流作用。一旦建立了長條圖表記錄儀，在沒有操作員或計算機的情況下，大多數(shù)記錄儀具有 足夠的內(nèi)部智能運行。精度取決于謄寫器的水平，并且你可能需要自己動手依比例輸入。 2鉛筆和紙 用鉛筆和紙的舊方式對于一些情形仍然是可行的，而且它便宜、易獲得、快速和容易開始。舉例來說 ,在 40 年以前 ,在一個著名的學院實驗室中 ,為追蹤用青銅做的坩堝中的溫度上升情況 的裝置是由熱電偶、繼電器、查詢臺、一捆紙和一支鉛筆。隨著技術(shù)的發(fā)展，通過電子設(shè)備，這個過程已經(jīng)得到簡化和變得比較精確、多用途和可靠。在這種情況下，操作者可能采用視訊遙控，通過大量檢測數(shù)據(jù)傳輸?shù)綑z測室，在那里收集、存儲和處理數(shù)據(jù)。監(jiān)測、記錄和分析數(shù)據(jù)在大范圍內(nèi)的應(yīng)用趨勢上升，包括設(shè)計 檢定產(chǎn)品發(fā)展狀態(tài)、環(huán)境的監(jiān)測、組成物的檢驗、臺式測試和處理故障檢查。t perceive small variations with the input signal. Furthermore, the electrical environment inside a PC tends to be noisy, with highspeed clocks and bus noise radiated throughout. Often, this electrical interference limits the accuracy of the PC plugin card to that of a handheld DMM .These cards also measure a fairly limited range of dc voltage. To measure other input signals, such as ac voltage, temperature or resistance, you may need some sort of external signal conditioning. Additional concerns include problematic calibration and overall system cost, especially if you need to purchase additional signal conditioning accessories or a PC to acmodate the cards. Taking that into consideration, PC plugin cards offer an attractive approach to data acquisition if your requirements fall within the capabilities and limitations of the card. 7. Data loggers Data loggers are typically standalone instruments that, once they are setup, can measure, record and display data without operator or puter intervention. They can handle multiple inputs, in some instances up to 120 channels. Accuracy rivals that found in standalone bench DMMs, with performance in the 22bit, accuracy range. Some data loggers have the ability to scale measurements, check results against userdefined limits, and output signals for control. One advantage of using data loggers is their builtin signal conditioning. Most are able to directly measure a number of different inputs without the need for additional signal conditioning accessories. One channel could be monitoring a thermocouple, another a resistive temperature device (RTD) and still another could be looking at voltage. Thermocouple reference pensation for accurate temperature measurement is typically built into the multiplexer cards. A data logger39。s college students are much more likely to use an automated process and analyze the data on a PC today, numerous options are available for gathering data. The optimal choice depends on several factors, including the plexity of the task, the speed and accuracy you require, and the documentation you want. Data acquisition systems range from the simple to the plex, with a range of performance and functionality. 2. Pencil and paper The old pencil and paper approach is still viable for some situatio