Abstract: The invention is a system and method for real-time monitoring and control of chemical sterilant concentration during all phases of a sterilization cycle by employing semiconductor-based sensor modules to selectively detect and measure the actual sterilant concentration in real time. In response to the transmitted concentration values, the sterilizer control system controls critical environmental parameters to maintain concentration levels within acceptable ranges for given time periods to assure sterilization efficacy and that the sterilant has been properly exhausted at completion of the cycle. The selectivity, sensitivity and accuracy of the semiconductor sensor are optimized by calibrating the sensor to baseline environmental parameters and by adjusting the sensor concentration reading when environmental parameters change during the sterilization cycle, by programming a new baseline value for the sterilant concentration at the new condition.

Abstract: The invention includes a system and a method for maintaining a selected concentration of a sterilant vapor during vapor phase sterilization. The system includes a sterilization chamber with a source of multicomponent vapor containing a sterilant vapor, an electromagnetic radiation source capable of generating radiation at a plurality of wavelengths, a radiation detector for detecting and quantitating the electromagnetic radiation absorbed at the wavelengths, the detector generating absorbance signals proportional to the concentration of the sterilant vapor in the multicomponent vapor, a microprocessor programmed to compare the absorbance signals with reference absorbance signals, to calculate the sterilant vapor concentration therefrom and to generate an output signal, and a controller to receive the output signal and to control addition of the sterilant vapor to the sterilization chamber to maintain a selected concentration of the sterilant vapor in the sterilization chamber during the sterilization process.