In general, a sample is a limited quantity of something which is intended to be similar to and represent a larger amount of that thing(s). The things could be

countable In mathematics, a set is countable if either it is finite or it can be made in one to one correspondence with the set of natural numbers. Equivalently, a set is ''countable'' if there exists an injective function from it into the natural numbers ...

objects such as individual items available as units for sale, or an

uncountable In mathematics, an uncountable set (or uncountably infinite set) is an infinite set that contains too many elements to be countable. The uncountability of a set is closely related to its cardinal number: a set is uncountable if its cardinal num ...

material. Even though the word "sample" implies a smaller quantity taken from a larger amount, sometimes full biological or

mineralogical Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the p ...

specimens are called samples if they are taken for analysis, testing, or investigation like other samples. They are also considered samples in the sense that even whole specimens are "samples" of the full population of many individual organisms. The act of obtaining a sample is called "sampling" and can be performed manually by a person or by automatic process. Samples of material can be taken or provided for testing,

analysis Analysis ( : analyses) is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle (38 ...

, investigation,

quality control Quality control (QC) is a process by which entities review the quality of all factors involved in production. ISO 9000 defines quality control as "a part of quality management focused on fulfilling quality requirements". This approach places ...

, demonstration, or trial use. Sometimes, sampling may be performed continuously.

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science Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence for ...

, a representative liquid sample taken from a larger amount of liquid is sometimes called an aliquot or aliquot part where the sample is an exact divisor of the whole. For example, 10mL would be an aliquot part of a 100mL sample.

Sample characteristics

The material may be

solid Solid is one of the State of matter#Four fundamental states, four fundamental states of matter (the others being liquid, gas, and Plasma (physics), plasma). The molecules in a solid are closely packed together and contain the least amount o ...

liquid A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, a ...

gas Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...

, a material of some intermediate characteristics such as

gel A gel is a semi-solid that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state, although the liquid phase may still dif ...

or sputum, tissue,

organism In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...

, or a combination of these. Even if a material sample is not countable as individual items, the quantity of the sample may still be describable in terms of its

volume Volume is a measure of occupied three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch). Th ...

mass Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementar ...

, size, or other such dimensions. A solid sample can come in one or a few discrete pieces, or it can be fragmented, granular, or powdered. A section of a rod, wire, cord, sheeting, or tubing may be considered a sample. Samples which are not a solid piece are commonly kept in a container of some sort.

References

{{reflist Analytical chemistry Clinical pathology Laboratories

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Sample characteristics

See also

References