A tanker and a method applying a detection device (2) for detection of the gas content of a liquid-containing fluid is disclosed. The detection device (2) comprises a pressure difference inducing member (28), a first flow sensor (32) arranged at the first side of the pressure difference inducing member and a second flow sensor (32) arranged at the other side of the pressure difference inducing member. The detection device comprises a control unit configured to determine the gas content of the liquid-containing fluid by means of the flow measurements made by the flow sensors (32, 32).The detection device (2) may comprise pressure sensors (30, 30) to measure the pressure on each side of the pressure difference inducing member (28). The pressure difference inducing member can be a valve or a pump or a pipe or a motor.The tanker may be used for collection of milk (especially suitable for small quantities) or other gas containing liquids, where the gas content needs to be measured accurately.
