:Volumetric pipette

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A volumetric pipette, bulb pipette, or belly pipette {{Cite web |url=https://glossary.periodni.com/glossary.php?en=volumetric+pipette |title=Volumetric Pipette |website=Chemistry Glossary }} allows extremely accurate measurement (to four significant figures) of the volume of a solution.{{Cite web |url=http://www.labdepotinc.com/c-878-volumetric-pipettes.php |title=Volumetric Pipettes |website=Labdepot, Inc }} It is calibrated to deliver accurately a fixed volume of liquid.

These pipettes have a large bulb with a long narrow portion above with a single graduation mark as it is calibrated for a single volume (like a volumetric flask). Typical volumes are 1, 2, 5, 10, 20, 25, 50 and 100 mL. Volumetric pipettes are commonly used in analytical chemistry to make laboratory solutions from a base stock as well as to prepare solutions for titration.

ASTM standard E969 defines the standard tolerance for volumetric transfer pipettes. The tolerance depends on the size: a 0.5-mL pipette has a tolerance of ±0.006 mL, while a 50-mL pipette has a tolerance of ±0.05 mL. (These are for Class A pipettes; Class B pipettes are given a tolerance of twice that for the corresponding Class A.)

A specialized example of a volumetric pipette is the microfluid pipette (capable of dispensing as little as 10 μL) designed with a circulating liquid tip that generates a self-confining volume in front of its outlet channels.{{Cite journal | last1 = Ainla | first1 = A. | last2 = Jansson | first2 = E. T. | last3 = Stepanyants | first3 = N. | last4 = Orwar | first4 = O. | last5 = Jesorka | first5 = A. | title = A Microfluidic Pipette for Single-Cell Pharmacology | doi = 10.1021/ac100480f | journal = Analytical Chemistry | volume = 82 | issue = 11 | pages = 4529–4536 | year = 2010 | pmid = 20443547}}