Gas Chromatograph Uses Varactor Bridge Flame Detector Amplifier for Enhanced Performance

Current amplifier circuit based on parametric (varactor bridge) op amp increases gas chromatograph's useful sensitivity, stability, and dynamic range. New design furnishes 5 × 10-12 amp full scale output for recorder and integrator drive.

Electronic engineers have no monopoly on sophisticated instruments for measuring the different components of an unknown input. Gas chromatographs, which have evolved as rapidly since 1950 as microwave spectrum analyzers, enable research chemists to separate tenths of microlitres of any vaporizable sample into its individual constituents, and to measure the quantity of each sample-constituent with better than 2% accuracy. Read full article



Harry Gill