How do we know that a pipet is a "blow out" pipet?

A "blow out" pipet is specifically designed for delivering a precise volume of liquid, and an important characteristic that distinguishes it is the presence of colored bands or frosted rings near the top. This design serves as a visual indicator that the pipet requires extra care when dispensing, specifically to "blow out" the last remaining drops of liquid after the main volume has been dispensed. This is essential for ensuring accurate measurements since any residual liquid could lead to volume errors.

The other characteristics mentioned, such as being used only with small volumes, having a wide opening, or being marked for multiple volumes, do not specifically define a blow out pipet. While these features might apply to various types of pipets, they do not indicate the requirement to blow out the last drop, which is a key purpose of the frosted rings or coloring on a blow out pipet. The ability to deliver accurate volumes is crucial in laboratory settings, particularly in water quality analysis, where precision is vital.