Design and application of flange type micro pressure liquid level transmitter in water tank liquid level measurement
With its own sensor and intelligent circuit board core technology, Huaheng transmitter manufacturers can extend and transform the core technology at low cost according to customer requirements to achieve personalized product customization. The main products are smart (SMART) series pressure transmitter, multi parameter transmitter, flowmeter, temperature sensor and level (liquid level transmitter manufacturer, which provides high performance price ratio industrial automatic transmitter manufacturer products for China's power, petroleum, chemical, metallurgical, cement, mining and other industries
Principle of micro pressure liquid level transmitter
The essence of micro pressure liquid level transmitter is to use pressure transmitter to indirectly measure liquid level, as shown in Figure 1. In fact, the pressure transmitter is installed on the side of the water tank at a certain height from the bottom. According to Pascal's law, the essence of its probe detection is the pressure value at the detection point. The pressure of the test point at the side wall of the water tank has the following relationship with the height from the point to the liquid level:
H=P/ ρ g （1）
H=P/ ρ g （1）
式中：H为检测点距液面的高度（m）；P为检测点的压强（Pa）； ρ 为液体的密度（kg/m 3 ）；g为重力加速度（m/s 2 ），取9.8。通过对检测点压强值的换算即可得到当前
Where: H is the height from the detection point to the liquid level (m); P is the pressure of the detection point (PA); ρ is the density of the liquid (kg / M 3); G is the acceleration of gravity (M / S 2), taking 9.8. Through the conversion of the pressure value of the detection point, we can get the current
检测点同液面的高度值，再加上检测点距水箱底的距离H 0 即可得到水箱的实际液位值。
The actual liquid level of the water tank can be obtained by the height of the detection point with the liquid level and the distance h 0 between the detection point and the bottom of the water tank.
Flange type micro pressure liquid level transmitter in water tank liquid level measurement design feasibility analysis of using micro pressure liquid level transmitter
In order to verify the feasibility of the micro pressure liquid level transmitter, an experimental platform is built, and the signal acquisition principle of the experimental platform is shown in Figure 2. Three micro pressure liquid level transmitters (essentially pressure transmitters) with different accuracy are installed at the same height by side wall installation. One input liquid level transmitter is installed at the top of the water tank. All the collected signals are transmitted to the control cabinet. The collected data of the pressure transmitter is converted into the corresponding liquid level value by program operation. At the same time, the actual liquid level of the water tank can be measured by steel ruler Standard value. The corresponding liquid level value of each transmitter can be read and downloaded from the human-computer interface.
Flange type micro pressure liquid level transmitter in water tank liquid level measurement design advantages and disadvantages of using micro pressure liquid level transmitter
Huaheng transmitter manufacturers have developed two core technologies, sensor and intelligent circuit board. Not only do they master all the core component technologies of all products, but also the accuracy of industrial automatic transmitter manufacturers is constantly improving, from level 0.2 to level 0.1. Through the extension of the core technology, other products for measuring flow and temperature can be deformed.
Considering the above data analysis results and practical application needs, the flange type micro pressure liquid level transmitter is used to measure the liquid level. Its advantages and disadvantages are as follows:
Flange type micro pressure liquid level transmitter is used in water tank liquid level measurement design. 1 advantages
(1) The measured liquid level is less affected by the impact of water flow, and has high accuracy and stability.
(2) The side wall of the water tank is installed for easy maintenance.
(3) The cost of the micro pressure liquid level transmitter with the same accuracy level is lower than that of the input liquid level transmitter.
Flange type micro pressure liquid level transmitter is used in water tank liquid level measurement design. 2 disadvantages
若直接采用压力变送器测液位，则需要在系统程序中增加压力值向液位高度值换算的计算步骤，并考虑安装高度值H 0 ；若采用自带换算功能的压力变送器（显示液位高度值）测液位，则无需换算步骤，但仍需要考虑安装高度值H 0 。
If the pressure transmitter is directly used to measure the liquid level, the calculation steps of pressure value conversion to liquid level height value need to be added in the system program, and the installation height value h 0 needs to be considered; if the pressure transmitter with its own conversion function (display liquid level height value) is used to measure the liquid level, the conversion steps are not needed, but the installation height value h 0 still needs to be considered.
The application of micro pressure liquid level transmitter, with the core circuit board design and production technology and metal capacitance as the core technology of sensor independent research and development and production, can fundamentally solve the problems of inaccuracy and maintenance difficulties caused by large fluctuation of monitoring value of traditional input liquid level transmitter. Although it is necessary to convert the monitoring value through the control program, for the engineering unit, it can be solved by unifying the installation dimension and standard. As the key part of the secondary water supply control system, the change of this monitoring mode is of great significance to ensure the stable operation of the secondary water supply system. With the secondary water supply becoming more and more intelligent, it is necessary to ensure the accuracy and stability of monitoring liquid level data,