a glass tube with a fine bore and thick walls, used in thermometers, etc
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
How to use capillary tube in a sentence
Now heat the bulb again, and at the same time heat the capillary tube over a second burner.
The thermometer is filled and the top of the capillary tube closed by the use of a small blowpipe flame.
The capillary tube is introduced and sealed in position, care being taken to expand the joint a little.
Cut off the capillary tube exactly at the upper level of the column of mercury, invert it and allow the mercury to run out.The Elements of Bacteriological Technique | John William Henry Eyre
With a glass-cutting knife cut the capillary tube through at the point "b," and allow the mercury to run out.The Elements of Bacteriological Technique | John William Henry Eyre