A mass flow measuring sensor includes: an oscillatable measuring tube bent in a tube plane; an oscillation exciter for exciting bending oscillations in a bending oscillation use-mode; two oscillation sensors for registering oscillations; a support system; and a measuring sensor housing; wherein the support system has support system oscillation modes, including elastic deformations of the support plate; wherein the support plate is cut to form a number of spirally shaped spring securements, via which the support plate is secured to the measuring sensor housing with oscillation degrees of freedom, whose eigenfrequencies are lower than a use-mode eigenfrequency of the bending oscillation use-mode, wherein the use-mode eigenfrequency is lower than the eigenfrequencies of the support system oscillation modes, wherein a calibration factor describes a proportionality between a mass flow through the measuring tube and a phase difference between oscillations of the measuring tube oscillating in the bending oscillation use-mode.