Mechanical working principle of float level gauge

The most commonly used measurement terminal in hydrological measurement is the liquid level gauge. According to the measurement methods, it can be roughly divided into mechanical float type, photoelectric float type, ultrasonic type, laser type, vibrating wire type and other forms, which have their own advantages and disadvantages. Both mechanical float type and photoelectric float type use the method of mechanical gear deceleration to generate carry and retreat to form code. In order to generate reliable code, gray code is generally used for output. The advantages of this liquid level gauge are relatively low price, while the disadvantages are complex machining, large operation resistance and short service life; Ultrasonic liquid level gauge and laser liquid level gauge have high measurement accuracy and no mechanical parts, so they have high reliability. However, it is found that they have certain requirements for reflective targets and are greatly affected by environmental factors. The most critical point is that their cost remains high due to the complex signal processing circuit, which is difficult to popularize at present; Vibrating wire liquid level gauge is mainly used for measuring liquid level in small range. In order to complete the long-term reliable measurement of large-scale liquid level with low cost, the author uses the low power consumption characteristics of MSP430 single chip microcomputer and the absolute position measurement function of photoelectric liquid level to design a new liquid level gauge – magneto-optical liquid level gauge, which is briefly introduced as follows.

1. Mechanical working principle of liquid level gauge
The liquid level gauge has a photoelectric code disk like the ordinary photoelectric liquid level gauge. The white part of the code disk reflects light, while the black part absorbs light, and is installed at the center of the circle. The optocoupler is fixed on the shell of the liquid level gauge with the circuit board. When the liquid level changes, the float pulls the water level wheel to rotate, and the code disc installed on the same shaft also moves in a circular motion with the water level wheel. When the code disc rotates, the code disc will absorb or reflect the light from the optocoupler, so that the 8-bit optocoupler can output 8-bit gray code according to the relative position of the code disc and the optocoupler, The traditional photoelectric liquid level gauge uses a reduction gear to drive another code disk to rotate, so as to obtain the high-level code. However, this liquid level gauge abandons all gear reduction mechanisms and uses the installation angle of 120
Zhenhai base of national petroleum strategic reserve (hereinafter referred to as Zhenhai base) is considered to be one of the four strategic petroleum reserve bases with the largest scale and the fastest project progress. The reservoir area spans 1200 meters from north to South and 860 meters from east to west. There are 4 groups of 16 oil tanks in the first phase of the project. The construction will be completed before the third quarter of 2005. The whole project will be completed before the end of 2006. There are 52 oil tanks and a total of 5.2 million cubic meters of oil can be stored. The estimated budget of the project is 3.76 billion yuan.

This non-contact radar measurement technology based on the principle of frequency modulated continuous wave (FMCW) has high precision, maintenance free, high reliability and durability. With relevant accessories and pressure transmitters installed at the bottom of the tank, the metering system can not only provide accurate measurement parameters, including data such as liquid level / multipoint temperature / oil-water interface / online actual density, but also provide actual volume, standard volume or quality data according to API / ISO or national standard calculation formula. So as to provide real-time and accurate control basis for system management and ensure the accuracy and credibility of inventory measurement. For this technically challenging project, it aims to develop the most cost-effective and flexible automation scheme for the national strategic reserve project. At the same time, in the project of comprehensively upgrading and transforming the refined oil reserve under its management,

Post time: 25-04-22