Abstract: A capillary tube containing a sample is anaerobicly sealed by means of closure caps each comprising an end wall and a skirt portion. Each open end of the capillary tube is sealed by inserting the open tube end into the cap skirt portion, and in order to avoid that a volume of air is forced into the capillary tube, the space defined between the open tube end and the cap end wall is vented to the atmosphere through one or more venting passages defined in the walls of the closure cap or between the inner surface of the cap skirt portion and the adjacent outer peripheral surface of the capillary tube. The open tube end is brought into sealing engagement with sealing means on the cap end wall, and frictional engagement established between the inner surface of the cap skirt portion and adjacent outer peripheral surface parts of the capillary tube secures that said sealing engagement is maintained.

Abstract: The invention relates to an electrochemical measuring device for transcutaneous measurement of arterial partial gas pressure, especially partial pressure of oxygen or carbon dioxide. The measuring device comprises an annular mounting member having a skin contacting surface adapted to be fastened to the skin surface of a patient, and a sensor of the type having a semi-permeable membrane adapted to be releasably connected to the mounting member. In the connected position of the sensor, the membrane is axially spaced from the skin contacting surface of the mounting member so that the membrane, the inner wall of the annular mounting member, and the skin surface define a measuring chamber which may be filled with a gel or another medium, if desired.

Abstract: The invention relates to a membrane mounting device for mounting a membrane or foil in a stretched condition at one end of a rod-shaped or tubular member, such as a measuring electrode member. The mounting device comprises a membrane to be mounted as well as a resilient mounting ring for retaining the membrane in its mounted condition. The resilient mounting ring is preferably kept in a condition substantially free from tension. However, immediately before use of the mounting device the ring may be tensed or stretched, and one end of a rod-shaped or tubular member may then be inserted in the membrane mounting device whereby the membrane may automatically be mounted at the said end of the rod-shaped or tubular member.