Radiometric measuring apparatus for detecting a measurement variable in the form of a fill level, a limit level, a density and/or a mass flow, wherein the radiometric measuring apparatus has: - a scintillator device, wherein the scintillator device is designed to generate light pulses upon excitation by ionizing radiation; - an optoelectronic sensor device, wherein the optoelectronic sensor device is designed to convert the light pulses into a sensor signal; - a first signal processing unit, wherein the first signal processing unit is designed to process the sensor signal into a first measurement variable signal (MGSa); - a settable second signal processing unit, wherein the second signal processing unit is designed to process the sensor signal in a measurement setting into a second measurement variable signal (MGSb), wherein the second measurement variable signal (MGSb) corresponds to the first measurement variable signal (MGSa) in the case of a faultlessly processing first signal processing unit and a faultlessly processing second signal processing unit, and to process the sensor signal in at least one operating setting (BE1, BE2, BE3, BE4) into at least one operating variable signal (BGS1, BGS2, BGS3, BGS4), wherein the at least one operating variable signal (BGS1, BGS2, BGS3, BGS4) does not correspond to the measurement variable signals (MGSa, MGSb), - a setting unit, wherein the setting unit is designed to set the second signal processing unit in measurement variable time intervals into the measurement setting and in operating variable time intervals (BZI1, BZI2, BZI3, BZI4) that alternate with the measurement variable time intervals into the at least one operating setting (BE1, BE2, BE3, BE4); and - an evaluation unit, wherein the evaluation unit is designed to compare the first measurement variable signal (MGSa) and the second measurement variable signal (MGSb) with one another and, depending on a result of the comparison, to evaluate the first signal processing unit and/or the second signal processing unit as faultlessly processing or incorrectly processing, - wherein the first measurement variable signal (MGSa) and the second measurement variable signal (MGSb) each have a measurement information, and - wherein the at least one operating variable signal (BGS1, BGS2, BGS3, BGS4) has a closed-loop control information, a noise edge position information (RKPI), a hightemperature measurement information (HTMI) and/or a cosmic ray information, wherein the closed-loop control information may depend on a disturbance variable to be compensated. - a scintillator device, wherein the scintillator device is designed to generate light pulses upon excitation by ionizing radiation; - an optoelectronic sensor device, wherein the optoelectronic sensor device is designed to convert the light pulses into a sensor signal; - a first signal processing unit, wherein the first signal processing unit is designed to process the sensor signal into a first measurement variable signal (MGSa); - a settable second signal processing unit, wherein the second signal processing unit is designed to process the sensor signal in a measurement setting into a second measurement variable signal (MGSb), wherein the second measurement variable signal (MGSb) corresponds to the first measurement variable signal (MGSa) in the case of a faultlessly processing first signal processing unit and a faultlessly processing second signal processing unit, and to process the sensor signal in at least one operating setting (BE1, BE2, BE3, BE4) into at least one operating variable signal (BGS1, BGS2, BGS3, BGS4), wherein the at least one operating variable signal (BGS1, BGS2, BGS3, BGS4) does not correspond to the measurement variable signals (MGSa, MGSb), - a setting unit, wherein the setting unit is designed to set the second signal processing unit in measurement variable time intervals into the measurement setting and in operating variable time intervals (BZI1, BZI2, BZI3, BZI4) that alternate with the measurement variable time intervals into the at least one operating setting (BE1, BE2, BE3, BE4); and - an evaluation unit, wherein the evaluation unit is designed to compare the first measurement variable signal (MGSa) and the second measurement variable signal (MGSb) with one another and, depending on a result of the comparison, to evaluate the first signal processing unit and/or the second signal processing unit as faultlessly processing or incorrectly processing, - wherein the first measurement variable signal (MGSa) and the second measurement variable signal (MGSb) each have a measurement information, and - wherein the at least one operating variable signal (BGS1, BGS2, BGS3, BGS4) has a closed-loop control information, a noise edge position information (RKPI), a hightemperature measurement information (HTMI) and/or a cosmic ray information, wherein the closed-loop control information may depend on a disturbance variable to be compensated.