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.
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.
Colorimeters measure the absorbance and transmittance of light through a fluid sample.
A conductivity meter measures an aqueous solution’s ability to carry an electrical current.
Gas and flame detectors determine the presence of a gas or fire, respectively. Gas monitors check or regulate the amount of gas present. The gas detectors pictured below detect carbon monoxide and hydrogen sulfide.
Humidity is a measure of the amount of water vapor in the air. It is generally reported as relative humidity, absolute humidity, or dew point temperature.
Level measurement devices can detect, indicate, and/or help control liquid or solid levels. Level measurement devices can be separated into two categories: direct, or mechanical, measurement and electronic measurement.
pH meters and controllers are used to measure and monitor the pH level of a substance.
There are many types of instruments used to measure absolute or gauge pressure. Pressure measurement devices can be separated into two categories: mechanical and electronic.
Refractometers measure the refraction of a beam of light in a fluid to determine the concentration of a substance dissolved in it.
Sight flow indicators (SFIs) allow plant engineers to monitor the flow and condition of gases, liquids, or granular solids in a system.
Spectrometers use light wavelengths to investigate the chemical composition of a sample. Atomic spectrometers use an analytical method by which one or several elements in unknown mixtures can be detected.
Temperature is the measure of the average internal energy possessed by the molecules of a substance. There are four popular units of temperature.
Turbidimeters are used to measure the relative clarity of a fluid by measuring the amount of light scattered by particles suspended in a fluid sample. Pictured below are a laboratory and portable turbidimeter.
Viscosity is a material’s resistance to flow under an applied stress, expressed as shear stress divided by shear rate.