A conductivity meter measures an aqueous solution's ability to carry an electrical current.
Colorimeters measure the absorbance and transmittance of light through a fluid sample.
Chromatography columns are used to separate mixtures. In any chromatography technique, there is a stationary phase that is usually solid or liquid and a mobile phase usually liquid or gas, that moves through it.
Analyzers are used to obtain gas samples and determine their composition. In-situ analyzers perform measurements right in the gas stream, while extractive analyzers remove a gas sample from the stream prior to analysis.