The Det‑Tronics 226585‑001 is a K‑series combustible‑gas transmitter (1 k, 2 k, or 8 k) that operates from 24 VDC and outputs a linear 4–20 mA signal to a controller. Common failure modes for this class include power supply dropout or voltage sag, sensor drift or fouling leading to erroneous output, internal relay or contact wear in the pressure switch section, and corrosion or loose wiring at the connector terminals. First‑check diagnostics: verify that the 24 VDC supply is present and stable; inspect all cable connections for continuity and secure crimping; and review the transmitter’s calibration log or error codes (if available) to identify any drift or fault flags before proceeding with component replacement or recalibration.[oss-gpt-20b]