| 摘要 |
The present invention is a self-contained apparatus for sampling fluids. The apparatus permits a fixed volume of conditioned sample to be delivered directly or through a sample valve to a means of detecting the sample. The amount of sample that gets into the atmosphere is negligible since all or all but a minuscule amount of the sample is returned to the vessel. Sample handling and maintenance are minimized, and calibration of analytical instrumentation is simplified. The self-contained on-line sampling apparatus comprises an isolation valve (10), a bleed/purge valve (12), a flow-through filter (14), optionally a self-purge valve (50), which preferably has 2-ports, a coupler (16), a block valve (18), a reference valve (20a), and optionally an auxiliary valve (20b), which preferably has 2-ports, a sampling valve (22), and a variable volume device (24) having a chamber (24a) and a reciprocating piston (24b), all in fluid communication and connected in series by way of a fluid communicating means (44), which extends from the tip of the sample probe (44a) to the variable volume device (24), but which does not include the variable volume device (24). A pressure controller (28) controls the pressure in the variable volume device (24) through closed-loop feedback control with a pressure sensor (26), an actuator (48), and the piston (24b) of the variable volume device (24).
|
