Abstract: An upright capillary tube is located at a position in a liquid container such that its lower end can be reached by the surface of the liquid level in the container as the liquid level rises and falls with changes in the amount of liquid in the container. A thermal sensor, e.g., a thermistor is provided on the capillary tube. As the liquid level rises and reaches the lower end of the capillary tube, the liquid rises in the tube due to surface tension. As the liquid in the capillary tube reaches the location of the thermal sensor, the sensor responds to a temperature change to detect the liquid level. The capillary sensing system can be miniaturized and is capable of superior sensitivity.

Abstract: A liquid vaporizing and feeding apparatus, having high heat transfer efficiency and capable of producing a large flow of vaporized gas from a small amount of liquid, utilizes an inclined vaporization plate which is held at a set temperature by a heater. Liquid, discharged by a nozzle in the vicinity of the upper end of the vaporization plate, is vaporized as it flows down an inclined upper face of the vaporization plate. When the volume of the liquid collected on the vaporization plate 20 reaches a designated amount, a level sensor 40 stops the inflow of liquid through the nozzle. Then, as vaporization continues, and the liquid level falls, the sensor causes inflow of liquid to resume. The cycle of stopping and resuming flow of liquid is repeated to maintain a constant liquid level.