| 摘要 |
PURPOSE:To eliminate the need for any level control means and to reduce the amount of water used by flowing a constant amount of water at all times in a pan, and allowing the excess thereof to overflow and to reflow into a tank. CONSTITUTION:The pan 12 of a humidifier 11 is mounted integrally in the inside bottom part of the thermohygrostat 10 of an environmetnal testing device, and the water in a tank 16 is supplied at all times into the pan 12 by a lifting pump 15. When the water level in the pan 12 exceeds prescribed height, the water is again reflowed into the tank 16 through an overflow pipe 14. On the other hand, an electric heater 17 of an approximate U shape and a sensor 18 for preventing dry firing are incorporated in the pan 12. Based on the detection output of a humidity sensor 19 projected in the thermohygrostat 10, the heater 17 is turned on and off by way of a humidity controller 20, thereby forcing the water in the pan to evaporate and humidifying the inside of the vessel 10. Thereby, the degradation in steam generating performance by being cooled by the temporarily inflowing water as with conventional devices is obviated, and the humidity control of high accuracy is accomplished with fast responsiveness. |
