We are exploring the ability of cross reactive sensor arrays to monitor the presence of chemical warfare agents. The sensing platform developed in our lab uses a variety of fluorescent microbead sensors, either 3 or 5 microns in diameter. The sensors have a wide range of surface functionalities and are coated with fluorescent dyes that change their emission properties upon interaction with analyte vapors. Every time the sensors are interrogated with light they photobleach which leads to signal loss and a decreased array lifetime. In order to monitor for long periods of time, a strategy has been developed that extends the array lifetime. Here, we implement a method to increase the lifetime of an array by up to 10-fold, as we incrementally expose small sections of the array at a time. We divide the array into sections by moving an optical slit across the face of the fiber.