基于可调谐半导体激光吸收光谱技术的西林瓶检漏方法

Leakage Detection of Vial Based on Tunable Diode Laser Absorption Spectroscopy

冻干制品灌装过程极易使西林瓶出现裂纹,裂纹及塞子与瓶口装配不紧等都会导致空气进入西林瓶内,使瓶内的药品变质或变性。基于可调谐半导体激光吸收光谱(TDLAS)技术建立了西林瓶检漏测量系统,该系统可对西林瓶的密封性实现快速无干扰检测。通过分析参考光路与探测光路中水蒸气的物质的量分数差Δx与参考光路中水蒸气的物质的量分数xr之间的关系,得到了不同湿度环境下的检测阈值。首先对该系统的测量精度进行了验证,结果表明测量标准误差小于0.007%;然后在xr分别为1.29%、1.33%、1.89%、2.20%时,对10个西林瓶进行检测,4号和8号西林瓶在不同xr下的Δx均大于对应的阈值,判定为泄漏瓶,与实际泄漏情况相吻合。

The vials easily crack in the filling process of freeze-dried products. Cracks and loose assembly of the vial plugs causes air to enter the vials, and thus leads to the metamorphism or degeneration of the freeze-dried products. A measurement system based on tunable diode laser absorption spectroscopy （TDLAS） was developed for fast and non-invasive leakage detection of vials. By analyzing the mole fraction difference of water vapor between the detection light path and the reference light path （△x） and mole fraction of water vapor （xr） of the reference light path, the threshold at different conditions is obtained. The measurement accuracy of the system is validated firstly, and it reveals that the standard deviation of the system is less than 0. 007%. Then, ten vials are detected when xr is 1.29%, 1.33 %, 1.89%, 2.20%, respectively. Vials No. 4 and No. 8 are considered as leaked vials, since △x is larger than the corresponding threshold at various mole fractions of water vapor xr, and the results are in good agreement with the real situation.