A process for the preparation of thermostable enzyme glucose oxidase of high Transition temperature useful for biological processes of high temperature, said process comprising steps of silanizaton of the activated glass beads by evaporative deposition of Aminopropyl triethoxysilane in acetone, heating the silanated glass beads overnight at about 115\xb0 C. The method includes obtaining an augmented spectral correlation function of acquired digital signals based on a SCF of the digital signal and a conjugate SCF proposed in the present invention, calculating a statistic, and comparing it with a decision threshold simulated or calculated through a predetermined method to determine whether the digital signal is a wireless microphone signal. On assembly, the inner cylinder secured to the canister flange is positioned inside the outer cylinder secured to the canister flange, altogether forming a canister. The device may be closed for transportation, and opened for use. Breath tests for the detection of bacterial overgrowth, lactose intolerance and combinations thereof are presented.