Fire protection is one of the activities that follow the development of technology in real-time and implements all the innovations of a detection system. This paper presents a unique solution for the development of an autonomous robot for the prevention, detection, and extinguishing of fires by studying the problem of choosing the optimal early-detection sensor in the infrared part of the spectrum, which characterizes the highest level of excitation in the state of prevention. The robot is equipped with several different sensors arranged in a hierarchical structure. Thermal detection has proven to be a significant investment that can be adapted to the different complexity of the objects to be protected, taking into account image processing and modular implementation of the required sensors. To this end, it is necessary to calibrate systems for different thermal cameras. The calibration procedure on seven cameras and two pyrometers resulted in data required for input-data correction and anomaly detection. The results of the analysis confirmed that devices of a higher price range have a lower deviation from the reference value compared to low-cost technical solutions. At the same time, results were observed indicating malfunction of more expensive devices, whose data exceed the specified nominal accuracy. Thanks to the performed calibration procedure and the obtained results, the observed problem is not an obstacle for implementation in an autonomous robotic system and can be used to correct the input data required for computer analysis.