臭氧标准参考光度计一级校准周期考察

Investigation of the level 1 calibration period by ozone standard reference photometer

对不同量程的臭氧二级传递标准进行一级校准实验,结果显示量程分别为500 nmol/mol和1 000 nmol/mol时,所得校准曲线的斜率和截距均能够满足臭氧一级校准指标的要求。对臭氧二级传递标准开展臭氧一级校准时,应根据实际需求选择合适的量程。对于大多数的监测站点,臭氧二级传递标准量程范围选择为500 nmol/mol可满足要求。在相同实验条件下(选择串口连接模式、校准曲线浓度点个数为6个、臭氧二级传递标准量程为500 nmol/mol),考察臭氧一级校准的周期。36个月的考察结果显示臭氧一级校准曲线的斜率在0.992 7~1.010 5之间,平均斜率为1.001 9;截距在-0.437 3^-0.026 6 nmol/mol之间,平均截距为-0.211 5 nmol/mol;斜率的相对标准偏差为0.32%,截距的标准偏差为0.094 nmol/mol,均能符合臭氧一级校准指标的要求。结合国内外相关标准及我国环境空气臭氧监测质量管理需求,建议臭氧二级传递标准至少每12个月开展一次臭氧一级校准。

Ozone level 1 calibration of ozone level 2 transfer standard with different ranges was carried out. The results showed that the slopes and the intercepts of the calibration curves were all within the ozone level 1 calibration index with the range of 500 nmol/mol and 1 000 nmol/mol by ozone level 2 transfer standard. It was recommended to choose the right range as required when ozone level 2 transfer standard were calibrated. For the major monitoring sites, the range of 500 nmol/mol could meet the requirements. Furthermore, the ozone level 1 calibration period was observed with the same experiment conditions, which were serial communication port, 6 concentration points and the ozone transfer standard range of 500 nmol/mol. Within 36 months, the slopes were between 0.992 7 and 1.0105 with the average slope 1.001 9, and the intercepts were between -0.437 3 and -0.026 6 nmol/mol with the average intercept -0.211 5nmol/mol, while the relative standard deviation （RSD） of the slopes was 0.32% and the standard deviation of the intercepts was 0.094 nmol/mol. The calibration results were all within the ozone level 1 calibration index. Consulting the relevant standards and the quality management requirements of ambient air ozone monitoring currently in China, it was suggested ozone level 2 transfer standard to perform ozone level 1 cali- bration once every 12 months at least.