Abstract: A method and apparatus to close an end of a hollow thermoplastic tube is disclosed. The apparatus includes a female die with an interior shaped end in the configuration of the desired closed end of the tube. The shaped end of the die is heated to the softening point of the plastic. The portion of the die adjacent the shaped end is in contact with a heat sink to maintain that portion of the tube adjacent the closed end at a temperature at least 15.degree. F. below the softening point of the plastic to prevent deformation of the tube.

Abstract: An electronic computer which provides an accurate final temperature reading prior to the actual stabilization of the temperature sensor. An algorithm is provided which allows making only two temperature measurements at preselected times yet accurately predicts the end stabilization temperature. A temperature resistance varying is converted to a temperature-frequency varying signal, clocked into an up/down counter, then displayed digitally. A thirty second timing sequence is also digitally displayed for use when the invention is utilized for medical applications.