Data acquisition and computer

R. N. Goldberg, R. L. Nuttall, E. J. Prosen, A. P. Brunetti. Digital Data Acquisition and Computer Computation Applied to Calorimetric Experiments. Nat. Bur. Stand. Report 1971, 10437. 

The excellent performance of the instrumentation results from a combination of contributions from several components, i.e., the high sensitivity and stability of the infrared detection system, the data acquisition and computational procedures, and the stabilizer used. 

A relationship has been developed by means of which more valid values are obtained by GPC for the average degrees of polymerization for cellulose. This can be extended to other polymers. With automation of data acquisition and computer processing of data, a differential molecular weight distribution and complete information on DP of the sample are available in very short order with a low degree of error. The ready availability of narrow, well characterized polystyrene fractions for calibration makes this procedure highly attractive in view of the lack of similar standards of cellulose. 

It is recommended that the gamma spectrometry system shall be a fully integrated data acquisition and computation system comprising the following items (IAEA 295, 1989) ... 

LIQUID CHROMATOGRAPHIC DATA ACQUISITION AND COMPUTER PROCESaNG... 

In another type of measurement, the parallel between mechanical and electrical networks can be exploited by using variable capacitors and resistors to balance the impedance of the transducer circuit. These electrical measurements readily lend themselves to computer interfacing for data acquisition and analysis. 

Time Systems, McGraw-HiU, New York, 1985 Hawryszldewycs, Database Analysis and Design, Science Research Associates Inc., Chicago, 1984 Kham-hata, Microprocessois/Microcomputers Architecture, Software, and Systems, 2d ed.. Whey, New York, 1987 Liptak, Instrument Engineers Handbook, Chilton Book Company, Philadelphia, 1995 Melhchamp (ed.), Real-Time Computing with Applications to Data Acquisition and Control, Van Nostrand Reinhold, New York, 1983. 

The ion detection system consists of a high-gain electron multiplier and the signal digitizing system, along with a computer for data acquisition and manipulation. 

Let the distance between the injection point and the peak maximum (the retention distance on the chromatogram) be (y) cm and the peak width at the points of inflexion be (x) cm. If a computer data acquisition and processing system is employed, then the equivalent retention times can be used. 

Using equation (10), the efficiency of any solute peak can be calculated for any column from measurements taken directly from the chromatogram (or, if a computer system is used, from the respective retention times stored on disk). The computer will need to have special software available to identify the peak width and calculate the column efficiency and this software will be in addition to that used for quantitative measurements. Most contemporary computer data acquisition and processing systems contain such software in addition to other chromatography programs. The measurement of column efficiency is a common method for monitoring the quality of the column during use. 

The complete LDA system includes the appropriate transmission and detection optoelectronics, traverse mechanisms, computer-controlled signal processing, and a data acquisition and evaluation system. The LDA equipment is a powerful tool for the measurement of flow velocity and velocity fluctuation, as well as the local concentration of particles or droplets transported in the airflow. 

There are several limitations of the computer-based systems and some system characteristics, particularly simplified data acquisition and analysis, provide both... 

Computer Techniques McLafferty (Ref 63) has pointed out that the usefulness of elemental composition information increases exponentially with increasing mass, since the number of elemental combinations with the same integral mass becomes larger. There are compilations of exact masses and elemental compositions available (Refs 12a, 13 18a). Spectral interpretation will be simplified in important ways if elemental compositions of all but, the smallest peaks are determined. Deriving the elemental compositions of several peaks in a spectrum is extremely laborious and time-consuming. However, with the availability of digital computers such tasks are readily performed. A modern data acquisition and reduction system with a dedicated online computer can determine peak centroids and areas for all peaks, locate reference peaks, interpolate between them to determine the exact masses of the unknown peaks, and find within minutes elemental compositions of all ions in a spectrum (Refs 28b 28c)... 

All aspects of interferogram and experimental data acquisition and optical test rig control are provided by a computer program that also performs film thickness evaluation. It is believed that the film thickness resolution of the colorimetric interferometry measurement technique is about 1 nm. The lateral resolution of a microscope imaging system used is 1.2 /u,m. Figure 10 shows a perspective view of the measurement system configuration. This is an even conventional optical test rig equipped with a microscope imaging system and a control unit. 

An extruder for a polymer was controlled by a microprocessor based data acquisition and control system. The CAMILE system (Control And Monitoring Interface for Laboratory Experiments) connects the sensors and control elements of the extruder to a host MS-DOS computer. While a variety of variables are measured and controlled, this paper will consider only temperature control. 

In order to represent and reason with temporal information, we need to represent time explicitly and concisely. The discrete-time character of computer-aided data acquisition and control dictates that time should be represented as a sequence of strictly increasing time points ... 

The authors wish to acknowledge the help of W. E. Coiner and J. L. Sills, Jr. who contributed to data acquisition and analysis. Also, we wish to thank Professor A. E. Hamielec and Dr. A. Husain for providing us with computational software and for their helpful discussions throughout the course of this work. 

Electrochemical Measurements. The electrochemical instrumentation included (a) a PAR model 263A potentiostat, (b) a PAR PowerCV software for data acquisition and analysis, and (c) a Dell Pentium IV computer. 

Instrumentation requirements for SEC are somewhat simpler than those of other modes of HPLC, since mobile phase gradients are not used however, adequate computer support for data acquisition and processing is essential. Method development involves finding a suitable solvent for the sample and choosing a mixed bed column or, more often, a set of columns in series to match the pore size of the column(s) with the size distribution of the sample. 

Various analytical methods have made quantum leaps in the last decade, not least on account of superior computing facilities which have revolutionised both data acquisition and data evaluation. Major developments have centred around mass spectrometry (as an ensemble of techniques), which now has become a staple tool in polymer/additive analysis, as illustrated in Chapters 6 and 7 and Section 8.5. The impact of mass spectrometry on polymer/additive analysis in 1990 was quite insignificant [100], but meanwhile this situation has changed completely. Initially, mass spectrometrists have driven the application of MS to polymer/additive analysis. With the recent, user-friendly mass spectrometers, additive specialists may do the job and run LC-PB-MS or LC-API-MS. The constant drive in industry to increase speed will undoubtedly continuously stimulate industrial analytical scientists to improve their mass-spectrometric methods. 

Apparatus. Since all the polymer modification reactions presented in this paper involved gas consumption, an automated gas consumption measuring system was designed, fabricated and used to keep constant pressure and record continuously the consumption of gas in a batch type laboratory scale reactor. Process control, data acquisition, and analysis was carried out using a personal computer (IBM) and an interface device (Lab-master, Tecmar Inc.). 

---