**Standard for ammonia alarm values
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I asked about this. Currently, the range setting for ammonia alarms used in purchases is usually set at 100 PPM. But I don’t know why it’s set at 100 PPM. I’m not sure if there are any standards for ammonia alarms; if so, what are those requirements? Thank you!
Range: 0~100LEL; high alarm at 15%; very high alarm at 20%~25%
The second floor is not correct; ammonia requires toxicity detection, with the alarm threshold set at 30 mg/m3 and the first-level alarm set at 15 mg/m3, which can be converted to ppm
GB50493-2009 stipulates that: \"The measurement range for toxic gases should be 0~300% of the maximum allowable concentration or 0~300% of the short-term exposure allowable concentration.\"； When the measurement range of the existing detectors cannot meet the above requirements, the measurement range for toxic gases can be 0~30% of the immediate harmful concentration. ”This is the original normative text! The permissible exposure limit for ammonia over a short period is 30 mg/m3, while the concentration that causes immediate harm is 360 mg/m3. Calculating the measurement range based on a short-term exposure limit of 30 mg/m3 yields 118 ppm (90 mg/m3); generally, this value is rounded to 0–120 ppm. According to GBZ/T223-2009, alarms are divided into three levels: forecast, warning, and high-level alarm. The pre-alarm value should be 1/2 of OC-STEL, that is, 20 ppm ； The alarm value is 1 PC-STEL, which is equivalent to 40 ppm ； There is no specific specification for the overreporting value; it is determined based on the actual conditions on site, but it is generally 2 times PC-STEL, that is, 80 ppm. Some of the statements on the third floor are unprofessional.