A picoliter is a unit of measurement regarding liquid volume, and is a specific subdivision of the measurement of liquid volume known as a liter. In general, it is a very small measurement and is regarded as one trillionth of a liter of liquid. This type of measurement is used in various scientific and research fields, though it is not commonly used by most people when referring to observable quantities of liquid. A picoliter may sometimes be referred to when discussing printing and copying machines, often in reference to the size of a single drop of ink from the machines, as those that produce smaller drops of ink can create images of greater resolution.
As a measurement of liquid volume, the picoliter is exceptionally small and generally not something most people are likely to encounter. In comparison, an average raindrop is several hundred thousand picoliters in volume, assuming an average raindrop size of about 4 millimeters in diameter. This scale can be useful for nearly microscopic additions of chemicals, but is not a practical measurement for most people. As such, a picoliter is typically a unit of measurement found in scientific research and technology.
In relation to other measurements, a picoliter is about one trillionth of a liter in volume. Scientific notation of this size would be that one picoliter is equal to 1×10-12 liters. The typical abbreviation for this measurement is “pL,” though “pl” is also sometimes used. In relation to metric measurements, in which a liter is generally regarded as being one cubic decimeter, and a kiloliter is equal to a cubic meter, it is equivalent to 1,000 cubic micrometers. A micrometer is one millionth of a meter and a single cubic micrometer is equal to one femtoliter, which is the equivalent of one quadrillionth of a liter.
One of the few places that a person outside of scientific fields may encounter a picoliter as a unit of measurement is in regard to high quality printers and copiers. For any printer that uses direct applications of ink, the measurement of the volume of a single drop of ink used in the printing is equivalent to the smallest possible dot or pixel of color on the printed page. This means that printers that use smaller drops of ink can create smaller dots of color, and thereby have larger resolutions for printed images. As such, manufacturers often advertise the ink drop volume for comparison, and some printers produce drops of only a few picoliters in volume.