A method for preparing a ready-to-use medicament for use by a medicament user, comprising: pumping a first quantity of water into a mixing container in a fluid circuit (123, 125, 149) of a medicament preparation system, the first quantity of water being less than a total quantity of water required in a final batch of medicament; flowing concentrated medicament from a medicament container to the mixing container to form a fluid with the first quantity of water, and pumping the fluid in a circular path through the mixing container to form a first mixed fluid; performing a first conductivity measurement on the first mixed fluid; in response to a controller (141, 1002, 1006) of the medicament preparation system determining there is no error in a result of the first conductivity measurement, adding a second quantity of water to the first mixed fluid and pumping the first mixed fluid with the second quantity of water in the circular path through the mixing container to form a second mixed fluid, the second quantity of water being less than a remaining quantity of water required in the final batch of medicament; performing a second conductivity measurement on the second mixed fluid; and in response to the controller (141, 1002, 1006) determining there is no error in a result of the second conductivity measurement, adding a third quantity of water to the second mixed fluid and pumping the second mixed fluid with the third quantity of water in the circular path through the mixing container to form the final batch of medicament; performing a third conductivity measurement on the final batch of medicament; and in response to the controller (141, 1002, 1006) determining there is no error in a result of the third conductivity measurement, pumping the final batch of medicament to the medicament user. pumping a first quantity of water into a mixing container in a fluid circuit (123, 125, 149) of a medicament preparation system, the first quantity of water being less than a total quantity of water required in a final batch of medicament; flowing concentrated medicament from a medicament container to the mixing container to form a fluid with the first quantity of water, and pumping the fluid in a circular path through the mixing container to form a first mixed fluid; performing a first conductivity measurement on the first mixed fluid; in response to a controller (141, 1002, 1006) of the medicament preparation system determining there is no error in a result of the first conductivity measurement, adding a second quantity of water to the first mixed fluid and pumping the first mixed fluid with the second quantity of water in the circular path through the mixing container to form a second mixed fluid, the second quantity of water being less than a remaining quantity of water required in the final batch of medicament; performing a second conductivity measurement on the second mixed fluid; and in response to the controller (141, 1002, 1006) determining there is no error in a result of the second conductivity measurement, adding a third quantity of water to the second mixed fluid and pumping the second mixed fluid with the third quantity of water in the circular path through the mixing container to form the final batch of medicament; performing a third conductivity measurement on the final batch of medicament; and in response to the controller (141, 1002, 1006) determining there is no error in a result of the third conductivity measurement, pumping the final batch of medicament to the medicament user.