The Oxytherm+ advanced oxygen electrode system provides PC control of oxygen uptake or evolution measurements across a broad range of research applications up to 100% oxygen concentration. 2 versions of the system provide the ultimate in flexibility allowing studies of a wide range of samples from state respiration changes in mitochondrial suspensions in the Oxytherm+R (Respiration) to light response measurements of isolated chloroplast suspensions in Oxytherm+P (Photosynthesis).