ABSTRACT
The pressure measuring devices meant for measurements in fluid flow may broadly be grouped into manometers and pressure transducers. The pressure transducers used for fluid flow experimentation may be classified as electrical type, mechanical type, and optical type. The U-tube manometers, multitube manometers, and Betz-type manometers are some of the popular liquid manometers used for pressure measurements in fluid flow. The basic measuring principle of the liquid manometer is that the pressure applied is balanced by the weight of a liquid column. In addition to these manometers, an accurate barometer is essential for pressure measurements, since in manometers the pressures are invariably measured in terms of a difference in pressure from some known reference. Manometers measure the difference between a known and an unknown pressure by observing the difference in heights of two fluid columns. Inclined manometers are generally used for measuring very small pressure differences. Micro manometer is basically a precision U-tube manometer.
