Oxygen Enterprises, Ltd. (Oxygen Enterprises) is a privately held medical device company engaged in the design and development of instruments for basic research, medicine, and industry. The company is mainly focused on the development of new optical method for the measurement of oxygen which is called phosphorescence quenching. Its key product, PMOD 5000 is used to measure the phosphorescence lifetime of phosphors with lifetimes from 5 microseconds to more than 1 millisecond, by means of which oxygen pressure can be measured. The other products of Oxygen Enterprises include phosphors for oxygen measurement, and cool colors lamps for the scientific laboratory. The company is headquartered at Philadelphia in Pennsylvania, the US.