Twelve injector types are available for installation on SRI gas chromatographs. Up to five injectors may be mounted simultaneously on the Model 8610C or 8610D. The Model 410 can mount a gas sampling valve in addition to the On-column injector which may be upgraded. The Model 310 will accommodate a single On-column, Heated Flash Vaporization, Heated Split/Splitless, or PTV injector. Injector types are selected by the user depending on the particular measurement application, detection limit, and regulatory requirements. The On-column injector is standard equipment on every 8610, 410, and 310 GC. Heated Flash Vaporization, Heated Split/Splitless, and PTV injectors are all upgrades to the On-column injector.