A static pressure sensor is widely used to measure the liquid level in atmospheric and pressure vessels. It uses the piezoresistive effect of diffused silicon or ceramic sensing elements to convert static electricity into an electrical signal. It is extremely easy to install and calibrate. Its key feature is that the differential pressure sensor and electronic circuitry are encapsulated on the top of the container being measured, separate from the liquid, resulting in safer and more reliable performance.
The static pressure sensor features a precision-manufactured differential pressure core and an aluminum alloy or stainless steel housing. It has two pressure ports with threaded and plug designs, allowing for direct installation on the measuring pipeline or connection via a pressure tap. It is widely used in pressure process control for leak detection in industries such as boiler ventilation, underground ventilation, power generation, and coal mining, as well as in beverage bottles and cans containing liquids like paint and beverages.
Applications of hydrostatic sensors:
Hydraulic and pneumatic control systems; petrochemical, environmental protection, and air compression; power plant operation and inspection, locomotive braking systems; thermal power units; light industry, machinery, and metallurgy; building automation and constant pressure water supply systems; other automation and testing systems; industrial process detection and control; laboratory pressure calibration, etc.
The hydrostatic method utilizes the principle of hydrostatic pressure to measure the physical parameters of oil in a storage tank. Its principle is as follows: the liquid inside the tank exerts a hydrostatic pressure on a pressure sensor installed at the bottom of the tank. This pressure, multiplied by the average effective cross-sectional area S of the tank, yields the mass M of the liquid inside, as shown in formula (2-2). The liquid level height h can then be calculated, as shown in formula (2-3).
The mass of the liquid, M, is given by formula (2-2): M = P1 x S/g
The height of the liquid level h: h = P1/Pxg (Formula 2-3)
This demonstrates that a hydrostatic metering system can directly measure the weight of the liquid inside an oil storage tank. During this measurement, the weight of the liquid in the tank depends only on the pressure applied to the pressure sensor and is independent of other parameters such as density and temperature. The hydrostatic method is used to measure the mass of the liquid inside an oil storage tank. The density of the oil at storage temperature T can be calculated from the pressure difference between P1 and P2. Specifically, by measuring the pressure P1 at the bottom of the tank using the lower pressure sensor and the pressure P2 at the middle of the tank using the middle pressure sensor, the density P of the liquid inside the tank can also be calculated.
Features:
It boasts high accuracy in mass and density measurement, but its accuracy in liquid level measurement is only average. It has no moving parts, ensuring high reliability; it can perform online measurements and is highly adaptable to various oil types; however, density measurement errors can occur when the liquid level in the storage tank is low; density stratification caused by temperature-induced stratification within the oil storage tank can also lead to significant measurement errors; installation and maintenance are relatively complex.
