An infrared welding device comprising a machine base having at least two workpiece supports for two workpieces, the distance of which is variable, as well as at least one infrared radiator fixed at a movable tool holder of the machine base and introducible into the gap of the workpieces formed by the distance of the workpiece supports. A patient’s apnea problem can be diagnosed at home without supervision with a CPAP device which delivers a continuously minimum appropriate pressure for substantially the entire period of therapy. In use, an upper one of the elongated slots extends at an angle upwardly and forwardly of the second component, while the lower one of the elongated slots extends upright or upwardly and rearwardly of the second component.