| 摘要 |
A sampling apparatus is characterized by a housing having a bore extending therethrough, which is supported with one end of the bore communicating with the interior of a liquid containing vessel and with an opposite end of the bore being outside of the vessel. A plunger or cylinder rod is positioned in the bore and has an annular recess intermediate its ends of a length longitudinally of the plunger which is less than the length of the bore. A pneumatic cylinder is connected with the plunger at the opposite end of the bore for reciprocating the plunger in the bore to project the recess into the vessel to receive a sample of liquid therein, and to then move the recess from the vessel and to an intermediate point in the bore whereat a housing outlet port receives the sample. First and second seals on the plunger to opposite sides of the recess maintain a liquid seal between the one end of the bore and the outlet port during reciprocation of the plunger, and a third seal is on the plunger toward the opposite end of the bore. The third seal absolutely blocks passage of any sampled liquid to the pneumatic cylinder, and wipes the bore clean between the opposite end thereof and the outlet port with each reciprocation of the plunger.
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