The Servomex SERVOTOUGH Oxy 1900 is a digital paramagnetic oxygen analyzer designed for hazardous‑area use, featuring a non‑depleting sensor that delivers highly accurate %O₂ readings with minimal calibration. Common failure modes include sensor drift or saturation (often due to contamination or aging), power supply instability leading to erratic output, and communication errors on the RS‑232/USB interface caused by cable degradation or firmware glitches. First‑check diagnostics: verify 24 V DC input voltage and monitor the sensor’s temperature probe for overheating; inspect all wiring and connectors for corrosion or loose contacts; review the device’s error log via the operator panel to identify any sensor or communication faults before proceeding with calibration or component replacement.[oss-gpt-20b]