Abstract: A liquid meter has constituent elements including a body, an immersed rotatable measuring device, a totalizer, a sealed separation in a dry region, transmission elements for the movement of the measuring device to the totalizer. The constituent elements are arranged in the form of independent modules including a measuring module, a totalizing module, a locking module and a filtration module. The constituent elements include respectively complementary assembly elements permitting their assembly with the body of the meter and/or with each other to constitute the meter.