A method for operating a pump, and in particular a measurement circuit pump for measuring fuel consumption on an engine test stand, wherein a flow monitor having a certain switch point is provided in the pump line, the method being characterized by the following steps: - in advance, when the pump is new, ascertaining once a reference controlled variable (f R) for an actuator of the pump by ∘ starting the pump by substantially steadily varying the controlled variable of the actuator up to the switch point; and ∘ ascertaining a controlled variable associated with the switch point, and storing this controlled variable as the reference controlled variable (f R); - prior to use of the pump, carrying out a calibration step on the same pump by: ∘ starting the pump by substantially steadily varying the controlled variable of the actuator up to the switch point; ∘ ascertaining a controlled variable associated with the switch point, and defining this controlled variable as the calibration controlled variable (f K); ∘ ascertaining a controlled variable difference value (Δf) between the reference controlled variable (f R) stored for the pump and the flow monitor and the calibration controlled variable (f K); and ∘ calibrating the actuator of the pump based on the controlled variable difference value (Δf). - in advance, when the pump is new, ascertaining once a reference controlled variable (f R) for an actuator of the pump by ∘ starting the pump by substantially steadily varying the controlled variable of the actuator up to the switch point; and ∘ ascertaining a controlled variable associated with the switch point, and storing this controlled variable as the reference controlled variable (f R); ∘ starting the pump by substantially steadily varying the controlled variable of the actuator up to the switch point; and ∘ ascertaining a controlled variable associated with the switch point, and storing this controlled variable as the reference controlled variable (f R); - prior to use of the pump, carrying out a calibration step on the same pump by: ∘ starting the pump by substantially steadily varying the controlled variable of the actuator up to the switch point; ∘ ascertaining a controlled variable associated with the switch point, and defining this controlled variable as the calibration controlled variable (f K); ∘ ascertaining a controlled variable difference value (Δf) between the reference controlled variable (f R) stored for the pump and the flow monitor and the calibration controlled variable (f K); and ∘ calibrating the actuator of the pump based on the controlled variable difference value (Δf). ∘ starting the pump by substantially steadily varying the controlled variable of the actuator up to the switch point; ∘ ascertaining a controlled variable associated with the switch point, and defining this controlled variable as the calibration controlled variable (f K); ∘ ascertaining a controlled variable difference value (Δf) between the reference controlled variable (f R) stored for the pump and the flow monitor and the calibration controlled variable (f K); and ∘ calibrating the actuator of the pump based on the controlled variable difference value (Δf).