The thesis describes the process through which the previous system for drying sealing joints in the welding joints between the roof and the body side moulding of cars has been developed and implemented. Important building blocks for the system are sensors, actuators, power and control equipment. Infrared heaters used for drying the sealant are controlled by modulation technique. The modulation is influenced by the output value of PI controller which determines the time of operating the heaters. Aplication control programme is loaded on a programmable logic controller (PLC). When the PLC is connected to the PC, it allows supervisory control and visualisation. The control programme uses signals of sensors and encoders for protection the body side of a car and devices. Furthermore it allows dynamic changing of heating recipes for the body side. Temperature control is set so that the error between the actual and desired temperature in most cases is less than 1°C.