基于光纤布拉格光栅的压力蒸汽灭菌器气体质量监测

基于光纤布拉格光栅(Fiber Bragg Grating,FBG)的灭菌全过程物理参数实时动态监测系统,提出基于聚酰亚胺涂覆的FBG(Polyimide-Coated FBG,PI-FBG)对灭菌器气体的质量进行监测,研究其可行性和监测方法。评估PI-FBG的温度稳定性及温度灵敏度,通过考查合格灭菌器排气期和干燥期传感器的响应,得出动态温度及压力条件下传感器对水分子密度的响应,提出由PI-FBG和毛细不锈钢铠装FBG温度传感器配合判断灭菌期水蒸汽是否合格的方法。在灭菌器工作温度范围内,传感器具有良好的温度稳定性,温度灵敏度为0.0143 nm/℃;动态温度及压力条件下传感器对水分子密度的响应可用分段线性关系表述,线性段灵敏度分别为8.9942×10^-4,1.7837×10^-5,2.2272×10^-4和1.6236×10^-4nm/(g·m^-3)。在预真空期和灭菌期进行测试可有效地判断灭菌期水蒸汽的干燥及纯净特性。本研究及前期工作为压力蒸汽灭菌器物理参数的全面监测提供了全新的光纤传感方法,具有安全、便捷、成本低和免电磁干扰等优势。

Gas quality monitoring for sterilizer based on fiber Bragg grating

The monitoring of target physical parameters in sterilizers includes temperature and air pressure monitoring.The aim of air pressure monitoring is to ensure that the dry and pure saturated water steam is working properly for sterilization.In our previous study,we have accomplished real-time,dynamic temperature monitoring of the whole process of sterilization using fiber Bragg gratings(FBG).In this work,we aim to obtain an integrated monitoring system of physical parameters based on FBGs for sterilizers.The proposed method is based on a polyimide-coated FBG to monitor gas quality during sterilization.Firstly,we evaluate both temperature stability and sensitivity of the polyimide-coated FBG.Then,the response to water vapor density is examined during the exhaust and drying periods of the qualified sterilizer.Finally,a system is proposed for the monitoring of gas quality through a polyimide-coated FBG and for the monitoring of temperature by a FBG encapsulated in capillary stainless-steel tubes.The polyimide-coated FBG showed excellent temperature stability during sterilization with a sensitivity of 0.0143 nm/℃.The response of the sensor to water vapor density can be represented by the piecewise lines,and their individual sensitivities were 8.9942×10^-4,1.7837×10^-5,2.2272×10^-4and 1.6236×10^-4nm/(g·m^-3).The proposed sensing structure working within pre-vacuum and sterilizing periods can effectively evaluate the drying and pure characteristics of water steam during sterilization.This study provides a new method for the monitoring of physical parameters of the sterilizer,which has many advantages such as safety,convenience,low cost and no electromagnetic interferences.