Modular generator avoids problems associated with ppb and ppt standards
The 491M/B/SD Modular Gas Standards Generator dynamically blends precisely known VOC/TOC gas standards with parts-per-billion (ppb) and parts-per-trillion (ppt) analyte concentrations. Dynamic blending process circumvents the problems commonly associated with ppb and ppt standards. Modular, two-stage dilution approach uses permeation tubes with measurable rates to control analyte flow. Also allows “standard additions technique” to be used, ensuring accuracy in spite of significant, unknown dilution gas combination. Two modules provide two sequential stages of dilution. First-stage 491M/B combines the analyte flow from Trace Source permeation tubes with a precisely controlled flow of pure dilution gas to form a ppb concentration mixture. In second-stage 491M/SD, an aliquot of the ppb mixture is further diluted to form a ppt mixture. KIN-TEK Laboratories Inc., La Marque, Texas