仪器法与化学法测定防毒面具滤毒罐苯蒸气防护时间研究*

为研究仪器法和化学法对滤毒罐苯防护时间结果的一致性以及对防护时间判定的影响因素，参照强制性国家标准《呼吸防护 自吸过滤式防毒面具》（GB 2890—2009），通过选择不同的实验条件，测试4种不同滤毒罐对苯的防护时间，并对实验结果进行显著性差异检验和分析。结果表明:仪器法测定的防护时间小于化学法测定的防护时间；2种检测方法所测定的防护时间结果有显著性差异；测试浓度越高、气流流量越大、采样流量越大，2种方法测定防护时间的绝对差值越小。从防毒面具的安全性和与国外标准一致性考虑，建议采用仪器法判定防护时间。

Study on protection time of gas mask canister against benzene vapor measured by instrumental method and chemical method

In order to study the influence of instrumental method and chemical method on the benzene protection time of canisters,referring to the mandatory national standard GB 2890—2009 “Respiratory protection Non powered air purifying respirators”,the benzene protection time of four different canisters under different test conditions were tested,and the significant difference test and analysis of experimental results were carried out.The results showed that the protection time determinded by the instrumental method was obviously lower that that by the chemical method,and there were significant differences between the protection time measured by two test methods.The higher the test concentration,the greater the gas flow rate and the greater the sampling flow rate,the smaller the absolute difference between the protection time determinded by two methods.Considering the safety of gas masks and the consistency with foreign standards,it is recommended to use the instrumental method to determine the benzene vapor protection time of the canister.