I believe everyone knows that ammonia is not only toxic to the human body, but also burns and explodes. However, the concentration of ammonia poisoning caused by ammonia is much lower than that when it can burn and explode. Therefore, in order to ensure safety, under normal circumstances, ammonia alarms need to set relevant alarm values according to toxic and harmful gases. Do Ammonia Alarm need to set low and high limits for the alarm? The following is a brief introduction by yi yun Tian:

To consider the toxicity of ammonia, when the ammonia alarm is set, the alarm value of the ammonia alarm shall be set according to the occupational exposure limit of ammonia. GBZ 2.1-2019 Occupational exposure limits for hazardous factors in the workplace stipulate that the occupational exposure limit for ammonia is 20 mg/m. According to GBT Article 5.5.2 of 50493-2019 stipulates that the first-level alarm set value (under-reported value) for toxic gases shall be less than or equal to 100 OEL (occupational exposure limit), and the second-level alarm set value (over-reported value) shall be less than or equal to 200 OEL (occupational exposure limit).

according to GB 50058-2014 The schedule of the Code for Design of Electrical Devices in Explosive Hazardous Environments stipulates that the upper and lower limits of ammonia explosion are 15.00 per cent and 28.00 per cent, respectively. If the enterprise only needs to consider the characteristics of its combustion and explosion when setting, then the alarm value of the ammonia alarm can be set with reference to the explosion limit. In the GBT 50493-2019 Article 5.5.1 of the Petrochemical Combustible Gas and Toxic Gas Detection and Alarm Setting Standard stipulates that the primary alarm setting value (under-reported value) of combustible gas shall be less than or equal to 25% LEL (lower explosion limit); The secondary alarm setting value (over-reported value) of combustible gas shall be less than or equal to 50% LEL (lower explosion limit).

To sum up, we can see that the ammonia alarm needs to set the low limit and high limit of the alarm, so that when the ammonia alarm has a low or high alarm, it can better use sound and light alarm or other alarm methods, to remind people to take relevant safety measures. In addition, because ammonia is toxic and can burn and explode, the ammonia alarm needs to be set according to the on-site working conditions and user requirements. If there is no special requirement, the alarm value can be set according to the setting specification of the toxic gas alarm.