6.制作開題報告電子秤文獻(xiàn)翻譯

1、elligent Data Acquisition SystemEngineers often must monitor a handful of signals over extended periods of time,and then graph andyze the resulting data. The need to monitor, record andyze data arises in a wide range of applications, including the design-verificationstage of product development, env

2、ironmental chamber monitoring, componentinspection, benchtop testing and pros trouble-shooting.This application note describes the various methods and deviyou can use toacquire, record and todays sophisticated disadvantages of easelecting the approachyze data, from the simple pen-and-p data acquisit

3、ion systems. It discusses ethod and provides a list of questionst best suits your needs.r method to using the advantages andt will guide you inroductionIn geotechnical engineering, we sometime encounter some difficulties such as monitoring instruments distributed in a large area, dangerous environme

4、nt of workingsitet cause some difficulty for easy acs. In this case, operators may adoptremote control, by which a large amount of measured data will be transmitted to aobservation room where the data are to be collected, stored and prosed.The automatic data acquisition control system is able to com

5、plete the tasks asregular automatic data monitoring, acquisition and store, featuring high automation, large data store capacity and reliable performance.The system is comthe following features:ed of acquisition control system and display system, with1. No. of Channels: 32 ( can be increased or decr

6、eased according to users real needs.)2. Scanning duration: decided by user, fastest 32 pos/secondStore capacity: 20G( may be increased or decreased)Display: (a) Table of parameter (b) History tendency (c) Column graphics.Function: real time monitoring control, warning6. Overall dimen: 50cm50cm72cmDa

7、ta acquisition systems, as the name imps, are products and/or prosesused to collect information tooryze some phenomenon.he simplestform, a technin logging the temperature of an oven on a piece of pr isperforming data acquisition. As technology has progressed, this type of pros hasbeen simplified and

8、 made more accurate, versatile, and reliable through electronicequipment. Equipment ranges from simple recorders to sophisticated computersystems. Data acquisition products serve as a focal poin a system, tying together awide variety of products, such as sensorst indicate temperature, flow, level, o

9、rprere. Some common data acquistion terms are shown below:Data acquisition technology has taken giant leaps forward over the last 30 to 40years. For exle, 40 years ago, in a typical college lab, apparatus for tracking thetemperature rise in a crucible of sodiumtungsten- bronze consisted of a thermoc

10、ouple,a bridge, a lookup table, a pad of pTodays college students are mur andncil.ore likely to use an automated pros andyze the data on a PC Today, numerous options are available fathering data.The optimal choice depends on several factors, including the complexity of the task,the speed and accurac

11、y you require, and theation you want. Dataacquisition systems range from the simple to the complex, wiperformance and functionality.range ofPencil and prThe old pencil and pr approach is still viable for some situations, and it isinexpensive, readily available, quick and easy to get started. All you

12、 need to do is hook up a digital multimeter (DMM) and begin recording data by hand.Unfortunay, this method is error-prone, tends to be slow and requires extensivemanualysis. In addition, it works only for a single channel of data; while you canuse multiple DMMs, the system will quicklyes bulky and a

13、wkward. Accuracyis dependent on the transcribers level ostidiousness and you may need to scaleinput manually. For exle, if the DMM is not set up to handle temperature sensors,manual scaling will be required. Taking these limiionso account, this is often anacceptablemethod when you need to perform a

14、quick experiment.Strip chart recorderModern vers of the venerable strip chart recorder allow you to capture datafrom several inputs. They providermanent pr record of the data, and becausethis data is in graphical format, they allow you to easily spot trends. Onet up, mostrecorders have sufficientern

15、alelligence to run unattended without the aid ofeither an operator or a computer. Drawbacks include a lack of flexibility and relatively low accuracy, which is often constrained to a few percentage po s. You can typically perceive only small changes in the pen plots. While recorders perform well whe

16、nmonitoring a few channels over a long period of time, their value can be limited. Forex andple, they are unable to turn another device on or off. Other concerns include penpr maenance, pr supply and data storage, all of which translateor overuse and waste. Still, recorders are fairly easy to set up

17、 and operate, andofferrmanent record of the data for quick and simpleysis.Scanning digital multimeterSome benchtop DMMs offer an optional scanning capability. A slothe rear ofthe instrument accepts a scanner cardt can multiplex betn multiple inputs, with8 to 10 channels of mux being fairly common. D

18、MM accuracy and the functionalityinherenthe instruments front panel are retained. Flexibility is limitedhat it isnotsible to expandthe number of channels availablehe expanslot.An external PC usually handles data acquisition andysis.PC plug-in cardsPC plug-in cards are singoard measurement systemst t

19、ake advantage ofthe ISA or PCI-bus expanslots in a PC. They often have reading rates as high as100,000 readings per second. Counts of 8 to 16 channels are common, and acquireddata is stored directlyo the computer, where it can then beyzed. Because thecard is essentially part of the computer, it is e

20、asy to set up tests. PC cards also arerelatively inexpensive, in part, because they rely on the host PC to provideer, themechanical enclosure and the usererface.Data acquisition optionshe downside, PC plug-in cards often have only 12 bits of resolution, so youcant perceive small variations with the

21、input signal. Furthermore, the electrical environment inside a PC tends to be noisy, with high-speed clocks and bus noiseradiated throughout. Often, this electricalerference limits the accuracy of the PCplug-in card tot of a handheld DMM .These cards also measure a fairly limitedrange of dc voltage.

22、 To measure other input signals, such as ac voltage, temperature or, you may need some sort of external signal conditioning.concerns include problematic calibration and overall system cost, espeAdditionallly if you modateneed to purchase additional signal conditioning acsories or a PC tothe cards. T

23、akingto consideration, PC plug-in cards offer an attractive approachto data acquisition if your requirements fall withthe card.he capabilities and limiions ofData loggersData loggers are typically stand-alone instrumentst, once they are setup, canmeasure, record and display data without operator or

24、computerervention. They canhandle multiple inputs, in some instanfound in standalone bench DMMs, with accuracy range. Some data loggers haveup to 120 channels. Accuracy rivalstperformance in the 22-bit, 0.004-percentthe ability to scale measurements, checkresults against user-defined limits, and out

25、put signals for control.One advantage of using data loggers is their built-in signal conditioning. Most are able to directly measure a number of different inputs without the need foradditional signal conditioning acsories. One channel could be monitoring athermocouple, another a resistive temperatur

26、e device (RTD) and still another could be looking at voltage.Thermocouple reference compensation for accurate temperature measurement istypically builto the multiplexer cards. A data loggers built-inelligence helpsyou set up the test routine and specify the parameters of each channel. Once you havec

27、ompleted the setup, data loggers can run as standalone devi, much like a recorder.They store data locally inor more.ernal memory, which canmodate 50,000 readingsPC connectivity makes it easy to transfer data to your computer for in-depthysis.Most data loggers are designed for flexibility and simple

28、configurationand operation, and many provide the option of remote site operation via battery packsor other methods. Depending on the A/D converter technique used, certain dataloggers take readings at a relatively slow rate, espelly compared to many PCplug-in cards. Still, reading speeds of 250 readi

29、ngs/second are notmon. Keepindt many of the phenomena being monitored are physical in nature suchas temperature, prere and flow and change at a fairly slow rate. Additionally,because of a data loggers superior measurement accuracy, multiple readings andaveraging are not nesary, as they often are ipl

30、ug-in solutions.Data acquisition front endsData acquisition front ends are often modular and are typically connected to a PCor controller. They are used in automated test applications fathering data and forcontrolling and routing signals in otharts of the test setup. Front end performancecan be very

31、 high, with speed and accuracy rivaling the best standalone instruments.Data acquisition front ends are implemented in a number of formats, including VXIvers, such as the Agilent E1419A multifunction measurement and control VXImodule, and proprietary card cages. Although front-end cost has been decr

32、easing, these systems can be fairly expensive, and unless you require the high performance they provide, you may find their price to be prohibitive. On the plus side, they dooffer considerable flexibility and measurement capability.Data Logger ApplicationsA good, low-cost data logger with moderate c

33、hannel count (20 - 60 channels) anda relatively slow scan rate is moren sufficient for many of the applicationsengineers commonly face. Some key applications include:Product characterizationThermal profiling of electronic productsEnvironmental testing; environmental monitoringComponent characterizat

34、ionBattery testingBuilding and computer room monitoringPros monitoring, evaluation and troubleshooting No single data acquisitionsystem works for all applications. Answering the following questions may help you decide which will best meet your needs:1. Does the system maty application?What is the me

35、asurement resolution, accuracy and noise performance? How fast does it scan? What transducers and measurement functions are supported? Is it upgradeable or expandable to meet future needs? How portable is it? Can it operate as a standalone instrument?How much does it cost?Is software included, or is

36、 it extra? Does it require signal conditioning add-ons? What is the warranty period? How easy and inexpensive is it to calibrate?How easy is it to use?Can the specifications be understood? What is the usererface like? How difficult isit to reconfigure for new applications? Can data be transferred ea

37、sily to newapplications? Which application packages are supported?Data acquisition can range from pencil, pr and a measuring device, to ahighly sophisticated system of hardware instrumenion and softwareysis tools.Thestep for users contemplating the purchase of a data acquisition device orsystem is t

38、o determine the tasks at hand and the desired output, and then select thetype and scope of equipmentt meets their criteria. All of the sophisticatedequipment andysis toolst are available are designed to help users understandthe phenomena they are monitoring. The tools are merely a means to an end.智能

39、化系統(tǒng)工程師經(jīng)常要對很長時間內(nèi)的很多信號進(jìn)行監(jiān)測、畫圖和分析產(chǎn)生的數(shù)據(jù)。監(jiān)測、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?fàn)顟B(tài)、環(huán)境的監(jiān)測、組成物的檢驗、benchtop 測試和處理故障檢查。從簡單的紙筆方法到現(xiàn)在所使用的復(fù)雜的系統(tǒng)這些應(yīng)用筆記描述了你能獲得、和分析數(shù)據(jù)的很多種不同方法和裝置。每法的缺點和優(yōu)點，然后列出一張能夠指引你選擇適合你實際需要單。前言在工程上，有時遇到一些，諸如設(shè)備分散在大范圍內(nèi)，的工作環(huán)境很容易一些。在這種情況下，操作者可能采用視訊，通過大量檢測數(shù)據(jù)傳輸?shù)綑z測室，在那里收集、和處理數(shù)據(jù)。自動的控制系統(tǒng)能夠完成很多任務(wù)，像自動定時數(shù)據(jù)監(jiān)測，數(shù)據(jù)采集和，高度

40、自動化為特色，大量數(shù)據(jù)能力和可靠功能。自動的控制系統(tǒng)和顯示系統(tǒng)優(yōu)如下特點：123多通路數(shù)：32（根據(jù)使用者的需要增長或減少）掃描持續(xù)時間：由使用者決定，最快一秒種掃描 32 點容量：20G（可能增加或減少）顯示：（a）參數(shù)表 （b）歷史趨勢 （c）專欄圖表功能：實時監(jiān)測、控制和大體尺寸：50cm50cm72cm系統(tǒng)，正如名字所暗示的，是一種用來信息成文件或分析一些現(xiàn)象的產(chǎn)品或過程。在最簡單的形式中，技術(shù)將烤箱的溫度在一張紙上就是。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。設(shè)備從簡單的器發(fā)展到復(fù)雜的電腦系統(tǒng)。數(shù)據(jù)采集產(chǎn)品像聚焦點一樣為系統(tǒng)服務(wù)，和一系列產(chǎn)品一

41、起，諸如傳感器顯示溫度、水流、程度或者過程。技術(shù)在過去 30 到 40 年以來已經(jīng)取得了很大的飛躍。舉例來說,在40 年以前,在一個著名的學(xué)院中,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。今天的大學(xué)學(xué)生很可能在PC 機(jī)上自動處理和分析數(shù)據(jù)，有很多種可供你選擇的方法去數(shù)據(jù)。至于選擇哪法取決于多種，包括任務(wù)的復(fù)雜度、你所需要的速度和精度、你想要的資料等等。無論是簡單的還是復(fù)雜的，數(shù)據(jù)系統(tǒng)都能夠運(yùn)行并發(fā)揮它的作用。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。而你所需要的就是捕捉到多路數(shù)字信息（DMM），然后開始

42、用手?jǐn)?shù)據(jù)。不幸的是這種方法容易發(fā)生錯誤、數(shù)據(jù)變慢和需要太多的人工分析。此外，它只能單通道數(shù)據(jù)；但是當(dāng)你使用多通道 DMM 時，系統(tǒng)將很快變得非常龐大和呆笨拙。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。舉例來說, 如果 DMM 沒有配備處理溫度的傳感器,舊需要動手找比例?？紤]到這些限制，只有當(dāng)你需要實行一個快速實驗時，它才是一個可接受的方法。長條圖表儀現(xiàn)代多種版本的長條圖表儀允許你從多個輸入取得數(shù)據(jù)。他們提供數(shù)據(jù)的長備紙,因為數(shù)據(jù)是圖解的格式,他們易于現(xiàn)場數(shù)據(jù)。一旦建立了長條圖表儀，在沒有操作員或計算機(jī)的情況下，大多數(shù)儀具有足夠的智能運(yùn)行。缺點是缺乏靈活性和相對的精度低，時常限制

43、在百分點。你能很清楚地感覺到與筆只有小的改變。在多通道內(nèi)較長時間的，儀能發(fā)揮很好的作用，除此之外，它們的價值得到限制。舉例來說，他們不能夠與另外的裝置輪流作用。其他的顧慮就是筆和紙的,紙的供給和數(shù)據(jù)的,最重要的是紙的濫用和浪費(fèi)。然而，儀相當(dāng)容易建立和操作，為數(shù)據(jù)快速而簡單的分析提供永久的。數(shù)字掃描傳多用表一些 benchtop DMMs 提供可選擇的掃描能力。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 mux。固有的在儀器的前面嵌板中的受到限制。它的柔韌性也受到限制，因為它過可用通道數(shù)。外部的PC 機(jī)通常處理和分析。PC 機(jī)插件卡片PC 機(jī)插件卡片是單板測量系統(tǒng)，它利用 ISA 或 PCI 總線在 PC 機(jī)內(nèi)擴(kuò)大插槽。它們時常具有高達(dá)每秒 1000 的閱讀速率。8 到 16 通道是普遍的數(shù)據(jù)直接在電腦里，然后進(jìn)行分析。因為卡片本質(zhì)上是計算機(jī)的一部分,建立測試是容易的。PC 機(jī)卡也相對的便宜,一部分地，因為他們以來主機(jī) PC 去提供能源、機(jī)械附件和使用界面。的選擇在缺點上，PC 機(jī)插件卡片時常只有 12 字的容量,因此你不能察覺輸入信號的小變化。此外,PC 機(jī)內(nèi)的電子環(huán)境經(jīng)常很容易發(fā)出噪聲、產(chǎn)生高速率的時鐘和總線噪聲，電子接觸面限制PC 機(jī)插件卡片的精度。這些插件卡片也測量一定范圍的電壓。