Transmitter, comprising: a sensor module, having at least one sensor and one sensor electronics system, wherein the sensor outputs sensor signals and wherein the sensor electronics system treats the digitalized sensor signals with a transmission function and makes treated sensor measured values available at a digital interface; and a main electronics module, which is functionally connected to the sensor electronics system, wherein the main electronics module has a logic unit and a communication interface, wherein the logic unit is configured to receive the sensor measured values provided at the digital interface and to order the outputting of a measuring signal, which corresponds to the sensor measured values, via the communication interface, wherein the logic unit is configured to perform a monitoring function, wherein, in addition to receiving the sensor measured value currently provided, said monitoring function also consists of receiving the associated digitalized sensor signals, of calculating a control measured value using both a test function, which comprises the transmission function, and the associated digitalized sensor signals received, of performing a comparison between the control measured value and the sensor measured value and of ordering the communication interface to output an error signal in the event of deviations, wherein the logic unit is further configured to provide the control measured value to the sensor electronics system, wherein the sensor electronics system is configured to perform a comparison between the control measured value and the sensor measured value and, in the event of deviations, to directly order the communication interface to output an error signal via an alarm output. a sensor module, having at least one sensor and one sensor electronics system, wherein the sensor outputs sensor signals and wherein the sensor electronics system treats the digitalized sensor signals with a transmission function and makes treated sensor measured values available at a digital interface; and a main electronics module, which is functionally connected to the sensor electronics system, wherein the main electronics module has a logic unit and a communication interface, wherein the logic unit is configured to receive the sensor measured values provided at the digital interface and to order the outputting of a measuring signal, which corresponds to the sensor measured values, via the communication interface, wherein the logic unit is configured to perform a monitoring function, wherein, in addition to receiving the sensor measured value currently provided, said monitoring function also consists of receiving the associated digitalized sensor signals, of calculating a control measured value using both a test function, which comprises the transmission function, and the associated digitalized sensor signals received, of performing a comparison between the control measured value and the sensor measured value and of ordering the communication interface to output an error signal in the event of deviations, wherein the logic unit is further configured to provide the control measured value to the sensor electronics system, wherein the sensor electronics system is configured to perform a comparison between the control measured value and the sensor measured value and, in the event of deviations, to directly order the communication interface to output an error signal via an alarm output.