What is the alarm level set for on-site styrene flammability detectors?
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Dear teachers: Recently, we conducted tests on the combustible gas sensors in use using styrene (whereas toluene was used for previous tests). We filled mineral water bottles with a quarter volume of styrene liquid, and by squeezing these bottles against the gas sensors, we allowed the vapor inside to enter the sensors. We tested two gas alarms of type II and one alarm of type I; the concentration readings reached a maximum of 10% LEL, which is below the threshold of 25% required for an alarm to be triggered. I asked the technical department, and they said that styrene vapor has low volatility, so it does not trigger a level-1 alarm; therefore, they suggested changing it to a level-2 alarm. I’m not sure how your company sets this up; please help analyze it. Thank you!
Generally, the alarm levels of combustible gas detectors should be set based on factors such as the explosive hazard and concentration of the gas being detected. For flammable liquids such as styrene, the gas formed upon evaporation can cause explosions; therefore, a more sensitive alarm level should be set to issue an alert in a timely manner before the gas concentration reaches dangerous levels. However, due to the low volatility of styrene, the concentration measured by the equipment you are using cannot reach the first-level alarm value of 25%. Under such circumstances, to ensure safety on site, it may be considered to adjust the alarm level to a level 2 alarm; it is also necessary to consult with the relevant departments to confirm that such an adjustment will not pose any safety risks to factory operations or the health of employees. Additionally, it is recommended to use a dedicated styrene detector for testing in order to improve accuracy. -