Manometers, liquid column

Calibration of Gauges Simple liquid-column manometers... 

Fluid manometers are devices where the readout of the pressure differential is the length of a liquid column. The most fundamental implementation of this principle is the U-tube manometer. This is simply a tube of U shape filled with manometer fluid, as shown in Fig. 12.16. The pressure differential is applied at both ends of the tube, making the manometer fluid move downward in one limb and upward in the other, until the forces acting on the fluid are in balance. 

Inclined manometer A manometer in which the vertical movement of the liquid column is amplified by inclination of the U-shaped reading tube. 

The bubble-forming section consists of a control valve (needle valve type), a chamber, and the liquid column. It is customary to have flat glass plates as two sides of the column, to assist photography and visual observation of the phenomenon. A manometer is also provided to evaluate the pressure difference across the nozzle. 

Those that are based on the height of a liquid column (manometers)... 

Multiplying Gauges To attain the requisite precision in measurement of small pressure differences by liquid-column manometers,... 

Teorell studied the system (6.1-1)—(6.1.5) graphically, by the isocline method, and also numerically. He recovered most of the features observed experimentally. This study was further elaborated by several investigators. Thus, Kobatake and Fujita [5], [6] criticized the original model for invoking the ad hoc equation (6.1.5). These authors assumed instead instantaneous relaxation of the resistance to its stationary value while preserving the overall order of the relevant ordinary differential equation (ODE) system by including consideration of the mechanical inertia of the liquid column in the manometer tube. 

Liquid-Column Methods Liquid-column pressure-measuring devices are those in which the pressure being measured is balanced against the pressure exerted by a column of liquid. If the density of the liquid is known, the height of the liquid column is a measure of the pressure. Most forms of liquid-column pressure-measuring devices are commonly called manometers. When the height of the liquid is... 

Manometers consisting of liquid columns of, commonly, mercury or a fluid such as silicone oil, have been used extensively in the past to measure gas mixtures in, for example, experimental, static investigations of the overall kinetics of gas-phase reactions. They continue to be used in many applications, including the establishment of primary pressure standards in several countries. 

Slack tube manometer. The tubes on each side of the manometer are connected to pressrtre taps (or one is open to atmosphere). The difference in liquid columns is measured with a ruler positioned between them. 

Liquid-Column Manometers The height, or head, p = phg/g to which a fluid rises in an open vertical tube attached to an apparatus containing a liquid is a direct measure of the pressure at the point of attachment ancf is frequently used to show the level of liquids in tanks and vessels. This same principle can be applied with U-tube gauges (Fig. 10-la) and equivalent devices (such as that shown in Fig. 

---