| 摘要 |
<p>A controller, wherein the throttling range may be changed without affecting the calibration point, comprises a restrictive passage between an outer tube and an inner tube, the outer tube having one end connected to a source of pressure and the other end connected to atmosphere for establishing a linear pressure gradient along said restrictive passage, the inner tube having an output port at one end and an orifice for connecting the linear pressure gradient to the output port, and a controller for positioning the orifice along said pressure gradient.</p> |
