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From AI: What is the alarm threshold for a methanol detector? There is no fixed value for the alarm threshold of a methanol detector; it is determined based on the detection scenario (whether it is for detecting flammable gases or toxic gases), relevant **standards, as well as the actual requirements of the specific situation. The common alarm value settings are as follows: 1. Flammable gas detection scenario (methanol vapor). The lower explosive limit (LEL) of methanol is 6.0% VOL (in accordance with the GB 15322.1-2026 standard). Set value for level 1 alarm (low-level alarm): It is usually set at 25% LEL (i.e., 1.5% VOL or 15,000 ppm). Secondary alarm (high alarm) set value: Usually set at 50% LEL (i.e., 3.0% VOL or 30,000 ppm). Applicable scenarios: methanol storage areas, production workshops, kitchens, and other locations where there is a risk of explosion due to methanol vapors. II. Toxic gas detection scenarios (methanol vapor): The PC-TWA (time-weighted average permissible concentration) for methanol is 25 mg/m³ (according to the GBZ 2.1-2019 standard, this corresponds to approximately 19 ppm). Set value for level 1 alarm (low-level alarm): It is usually set at 100% OEL (i.e., 25 mg/m³ or 19 ppm). Secondary alarm (high alarm) set value: Usually set at 200% OEL (i.e., 50 mg/m³ or 38 ppm). Applicable scenarios: enclosed spaces, laboratories, sewage treatment facilities, and other locations where there is a risk of acute methanol toxicity. III. Practical setup recommendations: Equipment differences: Gas detectors from different manufacturers and of different models may have slightly varying default alarm settings; it is necessary to refer to the device’s manual for specific details. On-site adjustment: The alarm thresholds can be fine-tuned according to the actual conditions at the site (such as temperature, pressure, and leakage risks), but it is necessary to comply with the established principles outlined in relevant **standards (such as GB/T 50493-2019 \"Design Standards for Detection and Alarm Systems of Flammable and Toxic Gases in Petrochemical Industries\"). This ensures that the alarm thresholds enable timely warnings while preventing frequent false alarms. Suppose I am operating a methanol distillation unit and there is a slight leak at the site, but the concentration is below 1.5% VOL or 15,000 ppm; according to GB 50983, no alarm will be triggered. Does this mean that one is still exposed to low concentrations of methanol?