KIN-TEK has added an Automated Humidity Control option to the FlexStream Modular Gas Standards Generating System. Adding humidity allows simulation of real sample streams. The FlexStream System dilutes the emission from permeation or diffusion tubes with an inert gas, typically nitrogen or zero air, to create trace concentration (ppm, ppb and pptr) gas mixtures. An internal microprocessor sets the operating mode and adjusts dilution flow to achieve the required concentrations. The FlexStream HG fits into the system as the end module. A portion of the inert dilution gas is saturated with water and mixed with dry, trace component carrying gas to form the humidified mixture. Humidity is adjusted by varying the ratio of wet to dry gas. Typically, values from 20 to about 90% RH can be achieved. The system can also be controlled remotely by a PC or process computer using Modbus connectivity.