How should the alarm threshold and range of a toluene diisocyanate toxic gas detector be set?
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How should the alarm threshold and range of a toluene diisocyanate toxic gas detector be set? According to the calculations based on specification 50493, Cppm is approximately 0.0138 ppm; therefore, a range of 0–0.1 ppm was chosen. This range seems too small, but would a larger range not violate the specifications?
According to specification 50493, the alarm setting for toluene diisocyanate toxic gas detectors should be based on Cppm. If Cppm≈0.0138ppm, then the range of 0~0.1ppm is indeed small, but it allows for more precise detection. If there is concern that the range is too small, consider increasing it appropriately, while ensuring that the detector’s sensitivity and accuracy still meet the specified requirements. Generally, it is recommended that the range be at least slightly higher than the expected maximum concentration to provide sufficient detection range. In actual use, the detector should also be calibrated and tested regularly to ensure its accuracy. .
Your calculation is correct; the standard value for reference comes from GBZ2.1-2019, \"Occupational Exposure Limits for Hazardous Factors in the Workplace\". Note one thing: Clause 3.0.10 specifies the order of selection for OELs; when determining the occupational exposure limits for toxic gases, the highest permissible concentration, the time-weighted average permissible concentration, and the short-term exposure permissible concentration should be considered in that order of priority. If the instrument’s accuracy meets the OEL, then use the OEL; if not, use the IDLH as the alarm value