[en] Temperature transmitter is one of the most important transmitters in the nuclear reactor it is used for RTD (resistance temperature detector) signal conditioning. It has built-in current excitation, instrumentation amplifier, linearization and current output circuitry which amplifies the RTD signal and gives linearization to it. It is a part of a system to get temperature and monitoring it. This system is very cost and complicated. In this work a digital system is implemented by using micro controller techniques that replaces the existing system, one chip (PIC16f877) is used to build a digital system, which is more accurate and give more performance and low costs . RTD is the sensing element of temperature, its resistance increases with temperature. There are many types of transmitters in the reactor such as temperature, pressure, level and flow but temperature one is chosen because of temperature is one of the most important parameters in process control.