The LD1/2 leaf-disc electrode chamber is a simple device for measuring oxygen exchange from a 10cm² leaf disc mounted within a sealed, gas-tight chamber. The LD1/2 is constructed from black acetal with a cast acrylic top window allowing the sample to be evenly illuminated for photosynthesis measurements using either the LH36/2R LED light source (when connected to the Oxylab electrode control unit) or the LS2 high intensity white light source. A prepared S1 oxygen electrode disc mounts into the base of the LD1/2 with the dome of the electrode forming the floor of the sample chamber.