Perspective methods of monitoring ammonia leaks from sealed products and the problems of their application are considered. Experimental data obtained as a result of studies of an optical chemical sensor (OCS) are presented. A functional polymer modified with highly selective compounds to the target ammonia gas was used as a sensitive coating that applied to the surface of an OCS. The research was carried out using a special experimental setup. A gas mixture of ammonia was used in artificial air like a test substance. The static and dynamic characteristics of the sensor were determined at various concentrations of ammonia and under conditions of various temperatures. The obtained characteristics made it possible to determine the influence of changes in the ambient temperature on the sensor readings for various values of the ammonia concentration. The ways of optimizing considered OCS for solving the problem of gas leak control were determined, based on the obtained data.