| 摘要 |
A cylindrical body (1) contains two axially displaceable pistons (6,7) with sample fluid fed from an aperture in a pipe conduit, which is coupled to an inlet (21) in the body. From the body, the fluid is fed outwards via a tapping-off hole (26). The pistons are controlled so that one of them (6), closing the inlet in the rest position and locating against the other (7), leaves the second piston and simultaneously opens the inlet (21). Thus test fluid is introduced into a sample chamber formed between the pistons, and the volume of which is allowed to remain at a predetermined size. The pistons are moved in parallel so that the sample chamber ends up at the tapping hole. The second piston is then moved further towards the now stationary first piston so that the sample chamber volume is reduced to nil, causing all the sample fluid to be fed through the tapping-off hole. The inlet is closed by the second piston, and after the two pistons relocate against each other, they both return to the rest position. |
