外文翻譯---正確選擇數(shù)據(jù)采集系統(tǒng)

1、外文資料Selecting the Right Data Acquisition SystemEngineers often must monitor a handful of signals over extended periods of time, and then graph and analyze the resulting data. The need to monitor, record and analyze data

2、arises in a wide range of applications, including the design-verification stage of product development, environmental chamber monitoring, component inspection, bench top testing and process trouble-shooting.This applicat

3、ion note describes the various methods and devices you can use to acquire it, record and analyze data, from the simple pen-and-paper method to using today's sophisticated data acquisition systems. It discusses the ad

4、vantages and disadvantages of each method and provides a list of questions that will guide you in selecting the approach that best suits your needs.1. IntroductionIn geotechnical engineering, we sometime encounter some d

5、ifficulties such as monitoring instruments distributed in a large area, dangerous environment of working site that cause some difficulty for easy access. In this case, operators may adopt remote control, by which a large

6、 amount of measured data will be transmitted to a observation room where the data are to be collected, stored and processed. The automatic data acquisition control system is able to complete the tasks as regular automati

7、c data monitoring, acquisition and store, featuring high automation, large data store capacity and reliable performance. The system is composed of acquisition control system and display system, with the following feature

8、s: 1. No. of Channels: 32 (it can be increased or decreased according to user's real needs.)2. Scanning duration: decided by user, fastest 32 points/second3. Store capacity: 20G ( it may be increased or decreased)4.

9、Display: (a) Table of parameter (b) History tendency (c) Column graphics.5. Function: real time monitoring control, warning 6. Overall dimension: 50cm×50cm×72cmData acquisition systems, as the name implies, are

10、 products and/or processes used to collect information to document or analyze some phenomenon. In the simplest form, a technician logging the temperature of an oven on a piece of paper is either an operator or a computer

11、. Drawbacks include a lack of flexibility and relatively low accuracy, which is often constrained to a few percentage points. You can typically perceive only small changes in the pen plots. While recorders perform well w

12、hen monitoring a few channels over a long period of time, their value can be limited. For example, they are unable to turn another device on or off. Other concerns include pen and paper maintenance, paper supply and data

13、 storage, all of which translate into paper overuse and waste. Still, recorders are fairly easy to set up and operate, and offer a permanent record of the data for quick and simple analysis.4. Scanning digital multimeter

14、Some bench top DMMs offer an optional scanning capability. A slot in the rear of the instrument accepts a scanner card that can multiplex between multiple inputs, with 8 to 10 channels of mux being fairly common. DMM acc

15、uracy and the functionality inherent in the instrument's front panel are retained. Flexibility is limited in that it is not possible to expand beyond the number of channels available in the expansion slot. An externa

16、l PC usually handles data acquisition and analysis.5. PC plug-in cardsPC plug-in cards are single-board measurement systems that take advantage of the ISA or PCI-bus expansion slots in a PC. They often have reading rates

17、 as high as 100,000 readings per second. Counts of 8 to 16 channels are common, and acquired data is stored directly into the computer, where it can then be analyzed. Because the card is essentially part of the computer,

18、 it is easy to set up tests. PC cards also are relatively inexpensive, in part, because they rely on the host PC to provide power, the mechanical enclosure and the user interface. 6. Data acquisition optionsIn the downsi

19、de, PC plug-in cards often have only 12 bits of resolution, so you can't perceive small variations with the input signal. Furthermore, the electrical environment inside a PC tends to be noisy, with high-speed clocks

20、and bus noise radiated throughout. Often, this electrical interference limits the accuracy of the PC plug-in card to that of a handheld DMM .These cards also measure a fairly limited range of dc voltage. To measure other

21、 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 t