A method for installing and operating a Coriolis mass flowmeter operating having a measuring tube, wherein the measuring tube is excited to vibrate, a phase shift of the vibration of the measuring tube which is dependent on the mass flow of the measuring tube or a corresponding time difference is determined, the temperature of the measuring tube is determined and the corresponding mass flow is calculated using the determined time difference and the determined temperature by means of a computation rule. Highly accurate measurements are possible in that in the computation rule, at least one known theoretical or empirical material temperature dependence influencing the mass flow is taken into account by determining a device-specific temperature dependence of the mass flowmeter influencing the mass flow through a subsequent calibration process and the known theoretical or empirical material temperature dependence and the device-specific temperature dependence are used in determining the mass flow.