| 摘要 |
PURPOSE:To maintain the temp. in a thermostatic chamber in a specified state quickly and surely, by controlling hot wind and cold wind by the use of a pure fluid controlling element, and blowing the same into the chamber. CONSTITUTION:A pure fluid controlling element 12 is provided with an input port 13, and output ports 14, 15, and the respective output ports are connected by pipelines 16, 17 to a thermostatic chamber 10. An electric heater 18 is installed in the midway of the pipeline 16. The element 12 has a pair of control ports 20, 21. A desired air pressure is introduced into one port 20, and is opened to the atmosphere through an orifice 20a. The back pressure of a nozzle 23 facing a flapper 22 oscillated by a liquid sealing type temp. detector 24 is conducted into the other port 21. When the temp. in the chamber rises, the flapper 22 displaces in the direction of closing the nozzle 23, then the pressure on the port 21 side increases, thereby controlling the ratio of the air flowing through the ports 14, 15. Conversely, when the temp. drops, the back pressure of the nozzle decreases, and the pressure on the port 21 decreases, thus allowing much air to be fed into the port 14. |
