How many type of capillary tube?

There are three main types of capillary tubes:

1. Plain capillary tubes: These are the most common type of capillary tube and are made of glass or plastic. They have a uniform bore and are used for a variety of purposes, such as measuring the volume of liquids, transferring liquids between containers, and sampling fluids.

2. Graduated capillary tubes: These are capillary tubes that have a series of graduations or lines marked along their length. This allows for the accurate measurement of the volume of liquids. Graduated capillary tubes are used in a variety of applications, such as clinical chemistry, hematology, and microbiology.

3. Volumetric capillary tubes: These are capillary tubes that have a specific volume calibrated into them. This allows for the accurate dispensing of specific volumes of liquids. Volumetric capillary tubes are used in a variety of applications, such as dispensing reagents in chemistry, filling microplates, and preparing samples for analysis.