| 摘要 |
<p>A pressure transmitting device for a control or regulating system has a souble diaphragm arrangement mounted in a head (5, 6), the two diaphragms (7, 8) being parallel, coaxial and joined at their axes by a separating member (14) carrying a valve member (15) arranged to engage the end of a bleed nozzle (18) mounted in a chamber (17) to which a pressure fluid, such as air, is supplied. The outer diaphragm (8) is in contact with a fluid, the level or pressure of which is to be monitored, and an increase in pressure moves the arrangement so that the valve member (15) closes the nozzle (18) to provide a variation in the fluid pressure in the chamber (17) which variation is used as a control parameter. The space between the diaphragms is filled with a gas or liquid and the use of such an arrangement makes the transmitter less sensitive to temperature variations and more able to resist adverse pressure conditions than previously proposed transmitting devices with only one diaphragm. A control system employing the pressure transmitting device as a functional element thereof is also described.</p> |
