The Wasson-ECE Dynamic Mixer is a simple portable mixing device for diluting samples or certified standards using selected diluent gases. The device includes a digital mass flow controller (MFC) to easily adjust the dilution gas flow. Inert flow paths and heating Bridges eliminate adsorption and condensation problems when mixing gas standards containing sulfur, oxides or other reactive analytes. The diluted mixture is sent directly to the gas chromatograph (GC) sampling loop for analysis.