The invention relates to an articulated arm CMM, which is constructed in a modular way, and a modular assembling kit for constructing such an articulated arm CMM, comprising an articulated arm having a first end and a second end, wherein the second end is configured to support a tool. The articulated arm comprises at least two arm sections, connected to one another by pivot joints with integrated angle encoders. The arm sections are configured as modules having a PCB unit, said PCB unit comprises an elongated PCB section element and at least one PCB encoder element. The PCB encoder elements are configured to build an angle encoder and the PCB section elements comprise electronic transmission means for transmitting the encoder signals from the PCB encoder elements toward a circuit deriving the relative position between the arm sections.