Recommended for collecting oil samples, this Vampire Sampling Pump draws a vacuum of 27 inches of Hg (mercury). The patented tube coupling device accepts any size sampling tube (with an outside diameter of 3/16" through 5/16") without changing fittings. 

The sampling tube is inserted through the coupling device until the lower end extends below the top of the sample bottle. When the knurled knob is turned to tighten the seal, the vacuum draws fluid directly into the bottle without coming in contact with the pump. This patented feature allows multiple samples to be taken without cleaning the pump between samples.