Drawing Volume Tester RDVT-01

Background
A vacutainer blood collection tube is a sterile glass or plastic test tube with a colored rubber stopper creating a vacuum seal inside of the tube, facilitating the drawing of a predetermined volume of liquid. Vacutainer tubes may contain additives designed to stabilize and preserve the specimen prior to analytical testing. Tubes are available with a safety-engineered stopper, with a variety of labeling options and draw volumes. The color of the top indicates the additives in the vial.

Description
Vacutainer needle are double ended, with one side being encased in a thin rubber coating for safety. When the needle is screwed into the translucent plastic needle holder, the rubber needle is inside the holder, and the exposed needle will be inserted into the vein. When a vacutainer tube is inserted into the holder, its rubber cap is punctured by the inner needle and the vacuum in the tube pulls blood through the needle and into the tube. The filled tube is then removed and another can be inserted and filled the same way. The amount of air evacuated from the tube predetermines how much blood will fill the tube before blood stops flowing.