Product Overview:

Gas chromatography and mass spectrometry are indirect methods for determining organic compounds, requiring calibration (standardization) of the analysis system using standard samples. The 951A quantitative loop calibrator consists of a series of quantitative loop samplers and an adsorption tube preconcentrator, designed for calibrating VOCs analyzers in ambient air. Standard gas at 1 ppm is directly sampled through the quantitative loop without dilution, then purged with a fixed volume of carrier gas into the adsorption tube for concentration and focusing, followed by thermal desorption and detection in the analyzer. The calibrator can connect up to 6 quantitative loops of different volumes, enabling calibration at 6 different concentrations. Software control allows simultaneous thermal desorption and triggering of the GC for automatic instrument calibration.

Product Features:

• 1ppm standard gas cylinder directly enters the 951A calibrator; standard gas is sampled using different volume quantitative loops, then purged with a fixed volume of carrier gas into the preconcentrator and analyzer for calibration. Quantitative loop injection enables direct injection of high-concentration, small-volume standard gas
• A fixed volume of carrier gas purges the standard gas in the quantitative loop into the adsorption tube for concentration, equivalent to diluting the 1 ppm standard gas by the purge carrier gas volume. Larger purge carrier gas volume results in higher dilution multiples, allowing dilution of 1 ppm standard gas to the required ppb-level concentration
• The quantitative loop calibrator is used to calibrate the instrument, saving standard gas and eliminating the need for sampling canisters, gas distributors, or canister cleaning equipment, significantly reducing calibration costs
• 5–6 quantitative loops can be selected for multi-point calibration of the analyzer, meeting the requirements for preparing standard curves
• Changing the purge carrier gas volume allows calibration at various concentration series
• Direct injection calibration using quantitative loops provides excellent repeatability and high sensitivity