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.
pH meters and controllers are used to measure and monitor the pH level of a substance.
Viscosity is a material's resistance to flow under an applied stress, expressed as shear stress divided by shear rate.
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.
Temperature is the measure of the average internal energy possessed by the molecules of a substance. There are four popular units of temperature.
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.
Sight flow indicators (SFIs) allow plant engineers to monitor the flow and condition of gases, liquids, or granular solids in a system.
Refractometers measure the refraction of a beam of light in a fluid to determine the concentration of a substance dissolved in it.
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.
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.