臭氧监测仪实验室校准及稳定性测试

以国内监测系统在用的臭氧校准仪为二级传递标准对臭氧监测仪开展了实验室校准,通过计算单次校准所得校准曲线的斜率和截距,符合中国相关标准中关于臭氧监测仪的校准指标:多点校准所得校准曲线的斜率为0.95~1.05,截距为-5~5 nmol/mol。进一步对2台臭氧监测仪进行了稳定性测试,12个月内臭氧监测仪的斜率变化为0.976 05~1.008 42,截距变化为-0.669 00~0.577 93 nmol/mol,臭氧监测仪的斜率、截距均符合臭氧监测仪校准指标的要求。稳定性测试表明,TF 49i型臭氧监测仪和EC 9810型臭氧监测仪经校准后均可用于实验室内臭氧标准传递比对工作。实验中臭氧监测仪更换臭氧涤除器、仪器零件后校准曲线的斜率均有明显变化,建议更换耗材后需采用高浓度臭氧对臭氧监测仪进行饱和并再次校准。

Study on the Laboratory Calibration and Stability Test of Ozone Monitors

Ozone monitors were calibrated by TF 49ips as the ozone level-2 transfer standard in the laboratory. The single slope and the intercept of the calibration curve were studied, which were within the calibration index of ozone monitor by China''s relevant standards:The slope of the multipoint calibration curve was within 0.95-1.05 and the intercept was within -5~5 nmol/mol. Furthermore,the stability test of different manufacturers'' two ozone monitors was investigated with 12 months. The slope of the calibration curves were between 0.97605-1.00842 and the intercept were between -0.66900-0.57793 nmol/mol by ozone monitor 1 and ozone monitor 2, which could all meet the calibration index of ozone monitors by the different manufacturers. The stability test results showed that ozone monitors of TF 49i and EC 9810 could be used in ozone transfer standard after laboratory calibration.There were obvious changes on the slope of the calibration curves after the replacement of the ozone scrubber and the instrument parts, it was suggested that the ozone monitors need to be conditioned by high concentration ozone and to be calibrated after the change of the ozone scrubber and the instrument parts.