RKI Instruments H2S/CO/Isobutane 50% LEL/O2 81-0158RK-04

Methane and isobutane have different combustion properties and relative responses on catalytic bead LEL sensors. Monitors calibrated with methane are optimized for methane detection. Monitors calibrated with isobutane are optimized for propane and isobutane environments — such as LPG storage, forklifts, and propane heating systems. Check the monitor's operator manual or configuration sticker to confirm which LEL reference gas is required for calibration.

Only if the GX-6100 is configured for methane as the LEL reference. The 81-0154RK-04 uses methane (CH4) as the combustible reference, while the 81-0158RK-04 uses isobutane. Verify the sensor configuration in the GX-6100 operator manual or contact 800.829.9580 to confirm which blend is correct for a specific unit.

Yes. The 81-0158RK-04 is listed for the SDM-6100 automated calibration station alongside the GX-6100 monitor. Use a demand flow regulator when connecting to the SDM-6100 to ensure the station controls gas delivery efficiently without wasting cylinder contents.

Calibration gas is a hazardous material with a certified blend concentration and expiration date. Once shipped, cylinders cannot be restocked or re-certified. Verify monitor model, sensor configuration, and LEL reference gas type before ordering. Call 800.829.9580 for pre-purchase verification at no charge.

H2S-containing calibration gas blends in aluminum cylinders typically expire 12–18 months after the fill date. Isobutane blends are generally stable within that period when stored properly — upright, cool, dry, well-ventilated location away from heat sources. Check the cylinder label for the specific certification date at the time of receipt.

Yes. PK Safety services RKI Instruments monitors and calibration stations in-house with factory-trained technicians. Services for the GX-6100 include sensor calibration and replacement, functional testing, and full repair. Call 800.829.9580 to arrange service or request a return authorization.