A measuring sensor of a measuring device for detecting a mass flow, a viscosity, a density and/or a variable derived therefrom of a flowable medium, comprising: - a measuring tube arrangement for conducting the flowable medium, the measuring tube arrangement having at least one measuring tube, the at least one measuring tube having an inlet section and an outlet section; - at least one first exciter component of a vibration exciter for exciting the at least one measuring tube into vibrations, wherein the at least one excitation component is arranged on the at least one measuring tube; - at least one first sensor component of a vibration sensor for detecting the vibrations of the at least one measuring tube, wherein the at least one first sensor component is arranged on the at least one measuring tube; - a fixing body arrangement, the fixing body arrangement being connected to the at least one measuring tube in the inlet section and in the outlet section; characterized in - a connecting device for detachably connecting the measuring tube arrangement to a process line, wherein the connecting device having measuring tube connection openings to which the measuring tube arrangement is connected, wherein the connecting device is connected to the at least one measuring tube in the inlet section and in the outlet section; and wherein the measuring sensor comprises a closure device, wherein a form-locking and/or force-locking connection between the connecting device and the fixing body arrangement is formed by wayof the closure device. - a measuring tube arrangement for conducting the flowable medium, the measuring tube arrangement having at least one measuring tube, the at least one measuring tube having an inlet section and an outlet section; the measuring tube arrangement having at least one measuring tube, the at least one measuring tube having an inlet section and an outlet section; - at least one first exciter component of a vibration exciter for exciting the at least one measuring tube into vibrations, wherein the at least one excitation component is arranged on the at least one measuring tube; - at least one first sensor component of a vibration sensor for detecting the vibrations of the at least one measuring tube, wherein the at least one first sensor component is arranged on the at least one measuring tube; - a fixing body arrangement, the fixing body arrangement being connected to the at least one measuring tube in the inlet section and in the outlet section; characterized in the fixing body arrangement being connected to the at least one measuring tube in the inlet section and in the outlet section; characterized in - a connecting device for detachably connecting the measuring tube arrangement to a process line, wherein the connecting device having measuring tube connection openings to which the measuring tube arrangement is connected, wherein the connecting device is connected to the at least one measuring tube in the inlet section and in the outlet section; and wherein the measuring sensor comprises a closure device, wherein a form-locking and/or force-locking connection between the connecting device and the fixing body arrangement is formed by wayof the closure device. wherein the connecting device having measuring tube connection openings to which the measuring tube arrangement is connected, wherein the connecting device is connected to the at least one measuring tube in the inlet section and in the outlet section; and wherein the measuring sensor comprises a closure device, wherein a form-locking and/or force-locking connection between the connecting device and the fixing body arrangement is formed by wayof the closure device.