Introduction of pressure tube

Piezometer is a thin tube-shaped instrument for measuring the relative pressure of liquid. It is usually a glass tube. The upper end is open to the atmosphere, and the lower end is connected to the side wall of the container and connected to the measured liquid. The liquid in the tube rises along the tube to a certain height h. Based on this, the relative pressure of the liquid at the hole on the lower end of the tube can be calculated as P=γh, where γ is the bulk density of the liquid. To avoid errors caused by capillary action, the inner diameter of the piezometer should be greater than 0.5 cm. It can be used to monitor the dam body infiltration line, seepage pressure, groundwater level and seepage around the dam.
Product Introduction
The piezometer is an ancient and common seepage monitoring instrument. It relies on the height of the water column in the tube to indicate the size of the seepage pressure. It can be used to monitor the dam body infiltration line, seepage pressure, groundwater level and seepage around the dam. It is widely used in water conservancy, petroleum, chemical industry, engineering machinery manufacturing, coal mining, shipbuilding, aviation, automobile, medical equipment and other industries. The inner diameter of the piezometer should not be too small, generally about 1 cm, to prevent capillary phenomenon and surface tension. The wall of the measuring hole should be perpendicular to the direction of water flow, and the hole mouth should be smooth to avoid distortion of the measured pressure. In order to prevent the pulsating pressure from affecting the reading, holes can be drilled symmetrically in all directions on the outside of the pipe section, and then connected to a flat pressure ring with a small tube, and then connected to the pressure measuring tube. Figure 1 shows an ordinary liquid pressure measuring tube. By measuring the height h of the liquid column in the pressure measuring tube, according to the formula: P=yh, the pressure at the measuring point can be obtained, where y is the bulk density of the liquid in the pressure measuring tube. In actual measurement, in order to improve the measurement accuracy, an inclined pressure measuring tube is often used, as shown in Figure 2a. At this time, although the liquid pressure is still p and the height of the vertical liquid column is still h, the length of the observation section l has increased, l=h/sinα, α is the inclination angle of the pressure measuring tube, because sinα must be less than 1, the scale length l must be greater than h, and with different inclination angles α, the multiples of l over h are also different. When the pressure to be measured is relatively large and the height of the water column is too high to be convenient for measurement and reading, a U-shaped mercury pressure tube can be used instead.