A package containing a reference liquid for the calibration and/or quality control of blood gas analyzers. The reference liquid is enclosed in a flexible, gas-tight container without any gas bubbles in the container, and to avoid any danger of formation of gas bubbles, the total gas pressure in the liquid...http://www.google.de/patents/US4116336?utm_source=gb-gplus-sharePatent US4116336 - Package containing a reference liquid for blood gas equipment
