摘要目的 研究称量环境温度和湿度的变化对采样前后滤膜称量结果的影响.方法 在(18±1)℃和(28±1)℃2个温度下,调节天平室的湿度,于不同气象条件下对采集煤尘前后的测尘滤膜进行称量,计算采样后承载滤膜的增量(相同称量气象条件下的承载滤膜质量减去相对应的空白滤膜的质量),对结果进行比较分析.结果 空白滤膜和承载滤膜在(18±1)℃和(28±1)℃的称量结果波动范围分别为0.10～0.13 mg和0.06～0.09 mg,温度和湿度均变化时,称量结果波动范围为0.12～0.16 mg;各组承载滤膜增量均值在(18±1)℃和(28±1)℃的波动范围分别为0.07～0.10 mg和0.04～0.08 mg,温度和湿度均变化时,波动范围为0.09～0.14 mg.同一温度组内,空白滤膜组和承载滤膜组的称量均值随着湿度升高呈上升趋势,而各承载滤膜的增量与湿度不相关;在相同湿度下,(18±1)℃时承载滤膜增量高于(28±1)℃,差异有统计学意义(P＜0.01);除总尘高增量组外,其余各组称量均值在(18±1)℃随湿度升高的上升趋势比(28±1)℃更明显,差异有统计学意义(P＜0.01).当湿度相同时,各承载滤膜组(18±1)℃的增量均值高于(28±1)℃,差异有统计学意义(P＜0.01).结论 实验室温度和湿度的变化导致测尘滤膜称量结果的波动,湿度对采样前后滤膜增量影响不明显,但低温时滤膜增量高于高温时,会影响粉尘浓度测定结果.

abstractsObjective To assess the effects of the alteration of humidity and(or)temperature on weight of filters without and with ambient particulate matter in a balance room.Methods The mass of blank dust sampling filters were weighed under(18±1)℃ and(28±1)℃ respectively,with the humidity varying from 35% relative humidity(RH) to 100% RH in a balance room.Then the blank filters were divided into two groups and were used to sample total dust and respirable dust.After sampling,the loaded filters were reweighed under above conditions and the mass difference before and after the sampling were compared and analyzed.Results The vibration of the average mass of filters varied from 0.10 to 0.13 mg and from 0.06 to 0.09 mg under the temperatures of(18±1)℃ and(28±1)℃ respectively;When both the temperature and humidity changed,it varied from 0.12 to 0.16 mg.The deviation of average mass difference ranged from 0.07 to 0.10 mg and from 0.04 to 0.08 mg under the two temperatures mentioned above:When both the temperature and humidity changed,it varied from 0.09 to 0.14 mg.The average mass of blank filters and loaded filters were all positively correlated with the change of humidity (P＜0.01).No effects of humidity on the average mass difference of the loaded filters were observed.The average mass differences of loaded filters and blank filters under(18±1)℃ were significantly higher than that under(28±1)℃(P＜0.01) when humidity was not changed.Conclusion The alteration of humidity and (or) temperature in a balance room attributes to the deviation of the measurement of the mass of filters and thus affects the gravimetric measurements of ambient particulate matter.