Composite sample

a recombined coalbed sample produced by averaging together thickness-weighted coal analyses from partial samples of the coalbed, such as from one or more bench samples, from one ...

composite sample

Natural environment; Water

A series of water samples taken over a given period of time and weighted by flow rate.

composite sample, weighted

Natural environment; Water

A sample composed of two or more portions collected at specific times and added together in volumes related to the flow at time of collection. Compare grab sample

composite sampling scheme

Mining; General mining; Mineral mining

One in which different parts, or stages, of the sample are reached by differing methods.

freeboard

Chemistry; Analytical chemistry

The space provided above the resin bed in an ion-exchange column to allow for expansion of the bed during backwashing.

calibration reference

Chemistry; Analytical chemistry

Any of the standards of various types that indicate whether an analytical instrument or procedure is working within prescribed limits; examples are test solutions used with pH ...

relative stability test

Chemistry; Analytical chemistry

A color test using methylene blue that indicates when the oxygen present in a sewage plant’s effluent or polluted water is exhausted.

fusion tube

Chemistry; Analytical chemistry

Device used for the analysis of the elements in a compound by fusing them with another compound; for example, analysis of nitrogen in organic compounds by fusing the compound with ...

capacity

Chemistry; Analytical chemistry

In chromatography, a measurement used in ion-exchange systems to express the adsorption ability of the ion-exchange materials.

replication

Chemistry; Analytical chemistry

The formation of a faithful mold or replica of a solid that is thin enough for penetration by an electron microscope beam; can use plastic (such as collodion) or vacuum deposition ...