Model 491M-B-T creates trace concentration standards for mercury and mercury compounds. Standards are prepared dynamically by mixing small flow of mercury vapor with larger flow of clean dilution gas. Held at constant temperature between 80-120[degrees]C, Trace Source(TM) permeation tubes dispense minute flow of mercury vapor. Concentrations from below 500 pptv to over 100 ppbv are possible using single stage dilution with dilution flow rates between 250-5,000 cc/min.
Model 491M-B-T Gas Standards Generator is designed to create trace concentration standards for mercury and mercury compounds. Standards are prepared dynamically by mixing a small flow of mercury vapor with a much larger flow of clean dilution gas. Trace Source(TM) permeation tubes are used to dispense a minute flow of mercury vapor. The permeation tubes are held at constant temperature, usually 80[degrees]C to 120[degrees]C. Dilution gas flow is precisely measured and controlled using a thermal mass flow controller. The mercury vapor flow emitted from the permeation tube is measured by measuring the rate of weight loss from the tube. To maintain mixture integrity the mercury standard contacts only heated glass and Teflon[R] surfaces.
Concentrations from below 500pptv to over 100ppbv are possible using single stage dilution with dilution flow rates between 250 and 5000 cc/min. Concentrations are traceable to NIST through physical standards.