SIRF houses four isotope ratio mass spectrometers (IRMS): two Thermo Delta V instruments, one Delta Plus XP, and one MAT253. We operate a range of continuous-flow inlets for the analysis of solid, liquid, and gas samples. These include two Costech ECS4010 Elemental Analyzers for solid and liquid samples (carbon, nitrogen, and sulfur), a ThermoFinnigan Gas Bench for carbonate minerals, waters, and air samples, and two Thermo Trace Ultra GCs for compound-specific isotope analysis. The MAT253, Delta Plus XP, and MAT252 are configured with variable volume dual-inlets for materials prepared off-line. In addition, SIRF houses a trace gas preconcentrator inlet for the hydrogen and carbon isotopic analysis of methane, ethane, and propane.