Abstract: An infrared fluid analyzer with an improved sensitivity and signal to noise ratio is provided. The device includes a capacitor microphone for detecting absorption by the sample of characteristic infrared wavelength lines, and utilizes an electret material to electrically polarize the capacitive element. Also included are means for controlling the temperature of the infrared radiation source in order to stabilize the output thereof and increase the reliability of the instrument, and means for controlling the temperature of the fluid sample. In a double-beam embodiment of the invention, a gas-free reference cell is provided to further stabilize the instrument.

Abstract: An infrared fluid analyzer with an improved sensitivity and signal to noise ratio is provided. The device includes a capacitor microphone for detecting absorption of characteristic infrared wavelength lines by the sample and utilizes an electret material to electrically polarize the capacitive element in the microphone. The device is used to detect a stoppage of respiration in a person and thereby warn of the presence of an APNEA condition. The capacitor microphone generates a signal each time it detects an exhaled breath. When a timer senses an extended delay between signals, an alarm sounds indicating the presence of an APNEA condition.

Abstract: A vehicle tire with tractive elements for positive engagement with the ground surface is disclosed. The tire carcass has a tread including raised features. Means for positively linking tractive elements positioned radially outwardly of the tread to the raised features of the tread are provided in the form of a flexible but substantially inextensible belt positioned radially outwardly of the tread, and retainer elements positioned radially inwardly of the belt, the tractive elements being positioned radially outwardly of the belt and being releasably attached to the retainer elements for clamping the belt tightly therebetween. Inflation pressure within the carcass expands its crown region to maintain the belt in a taut condition. The retainer elements are sectionally constructed to facilitate assembly and disassembly of the tire.