I believe everyone knows that ammonia is the 1 flammable and toxic gas. When its concentration is too high, it will not only cause explosion hazards, but also stimulate the human body and threaten human health. Therefore, in some places where ammonia exists, in order to facilitate the control of ammonia concentration, the ammonia detector should set the corresponding alarm value, and once the alarm value is exceeded, an alarm signal will be issued to remind personnel to take corresponding measures in time. What is the alarm concentration of Ammonia detector ? The following is a brief introduction by yi yun Tian:

in" petrochemical combustible gas and toxic gas detection and alarm design standard "GB/T 50493 - 2019 appendix B common toxic gas and vapor characteristics it is stated in:

1. Occupational exposure limit for ammonia OEL(mg/m3) :

(1) Time-weighted average allowable concentration PC-TWA:20;

(2) Short-term exposure allowable concentration PC-STEL:30;

(3) Direct harmful concentration IDLH(mg/m3):360;

2. measurement range and alarm setting

(1 3) The measurement range shall meet the following requirements:

The measurement range of toxic gas should be 0~300 OEL; When the measurement range of the existing detector cannot meet the above requirements, the measurement range of toxic gas can be 0 ~ 30% IDLH; The measurement range of ambient oxygen can be O ~ 25% VOL;

(2) The alarm value setting of ammonia detector shall meet the following requirements:

The primary alarm setting for toxic gases shall be less than or equal to 100 OEL and the secondary alarm setting for toxic gases shall be less than or equal to 200 OEL . When the measurement range of the existing detector cannot meet the measurement requirements, the first-level alarm setting value of toxic gas shall not exceed 5% IDLH, and the second-level alarm setting value of toxic gas shall not exceed 10% IDLH.

(3) If the ammonia concentration in the environment exceeds the set alarm value, the instrument will alarm, and corresponding measures should be taken to prevent poisoning.

Therefore, in general, the primary alarm value of the ammonia gas detector is 25ppm and the secondary alarm value is 50ppm. The alarm point can also be set by itself. Like the occupational exposure limits in China (GBZ 2-2002) stipulates that the time weighted average allowable concentration value (TWA) of ammonia gas is 20 mg/m3, and the allowable concentration value (STEL) of ammonia gas for short time exposure is 30mg/m3.

It is worth noting that ammonia should be set with different values in different application scenarios. Therefore, the purpose and object of use must be clear in order to scientifically set safe alarm points. Specific application scenario settings, you can consult Yiyuntian!