Used in FlexStream™ calibration gas generator to produce ppm and ppb mixtures directly from pure gases, Trace Source™ 57 Series only use gas phase of compound. Controlling pressure in tube allows high-vapor pressure compounds – methane, ethane, ethylene – to be dispensed by permeation. Emission rate is proportional to compound pressure in tube, and attainable single-step dilution ratios from 1000:1 to >50,000,000:1 allow ppb mixtures to be made directly from pure analyte compound.