The real-time performance of a microcomputer system designed for dedicated control of gas chromatography and real-time analysis was studied to determine operating characteristics and accuracy of the peak-area integration algorithm. The software program developed to obtain peak areas used statistical criteria for the detection of the start, maximum value, and end of a chromatographic peak. The accuracy of the system was tested with propane-helium mixtures and by comparison to results obtained with off-line data reduction. The study showed that the real-time microcomputer system gave peak areas which were lower than the off-line results by less than 0.6 percent. The difference was shown to arise from truncation error in the double-precision octal mathematical subroutines, and to error in the assignment of a baseline at the peak-end.

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Real-Time Analysis of Gas Chromatograms with a Microcomputer System

A microcomputer system for on-line, real-time I simultaneous analysis and control of multiple gas· chromatographs is'described. LBL-4139 The system, incorporating the INTEL 8080 microprosser, is an improved version of an INTEL-8008-based·microcomputer system developed by the authors for real-time analysis and· control of a gas chromatograph. The new microcomputer system allows many gas chromatographs to share the microcomputer -· facilities, thus greatly expanding the system capacity at a low cost, without affecting the singl,e-user performance. This new achievement has been made possible by a high-speed central processing unit in the microcomputer and by special-purpose hardware and software developments. A new feature incorporated in the system is a parallel-asynchronous interface for teletype output operations. The interface enables simultaneous analytical and output functions without interfering with the timing of the data sampling process.

/pdf/a-microcomputer-system-for-analysis-and-control-of-multiple-ggorqeygsj.pdf

A MICROCOMPUTER SYSTEM FOR ANALYSIS and CONTROL OF MULTIPLE GAS CHROMATOGRAPHS

LBL-4138 A microcomputer system based on the Intel 8008 microprocessor has been .developed to perform real-time, on-line data acquisition and analysis of gas chromatographic data, and to control sampling and operation of the gas chromatograph. Real-time analysis is achieved by the novel method of interleaving subprograms for the sequential data acquisition and reduction steps, thereby minimizing memory requirements. The system contaiils a real-time clock for signal timing,and interfaces to a teletype and digital volt meter. A digital-to-analog converter is used to control the temperature of the gas chromatographic column, while a matrix of relays is able to actuate sampling values.

/pdf/a-microcomputer-system-for-real-time-monitoring-and-control-17jcts0jsc.pdf

G.M. Bobba

Papers

A Microcomputer System for Real-Time Monitoring and Control of Gas Chromatographs