Sewage tank level measurementSubmersible Level TransmitterUsing a static pressure input level gauge, the water volume in the sewage pool fluctuates greatly. The quality and quantity of petrochemical wastewater are closely related to the production process, and the wastewater generated in the process is continuously discharged. The composition of petrochemical wastewater is complex, and the wastewater contains a large amount of oil, sludge, heavy metals, etc. Due to the influence of raw materials, processes, etc., the pH of wastewater is unstable and may be strongly alkaline or strongly acidic. The pressure sensor is used as the core component of the equipment. Based on the principle of measuring the static pressure of the liquid in proportion to the height of the liquid, it converts the static pressure into a 4~20mADC standard current signal for output. Under the influence of harsh environments, this kind of liquid level gauge often suffers from failures such as the detection element being blocked by oil in the sewage pool and the equipment seal leaking. This not only causes operational measurement failures in the process, but also brings a lot of workload to instrument maintenance personnel.

Acceleration is directly proportional. The proportional relationship between them is reflected by the formula P=value. P is the pressure, the medium density is B, the gravity acceleration is G, and the depth of the measuring point is H. The practical application is to use the piezoresistive effect of diffused silicon or ceramic sensitive elements to convert static pressure into electrical signals and transmit them to indicating instruments to display changes in liquid level. After repairing the liquid level gauge, it was found that the detection error of the detection component was large, and the detection sensor and protective shell seal leaked, causing instrument failure. Repairing the probe is prone to secondary failures, and the cable seal leaks again, causing damage to the pressure sensor and making the repaired input-type liquid level meter unable to operate stably for a long time. At the same time, the sealing requirements between the pressure sensor component of the input liquid level gauge and the measurement medium are relatively high. Due to the high failure rate of this liquid level gauge, it needs to be replaced several times a year, and more than a dozen pressure sensors are replaced every year, which greatly increases the cost of equipment maintenance. Therefore, it is necessary to find a better and more reasonable liquid level measurement method to replace the original measurement method.

Servo level gauge.

Advantages: It can not only measure the medium liquid level, but also measure the density, oil-water interface, medium average density and density distribution.

Disadvantages: When the viscosity of the measurement medium is high, the measurement error of the servo input liquid level meter is large, and it is not suitable for liquid level measurement of these media.

Air blowing liquid level gauge.

Advantages: The liquid level measurement system composed of the air blowing device has no moving parts. Except for the air blowing pipe, other measuring parts do not contact the measured medium. Full mechanical structure, good sealing, low failure rate and low maintenance.

Disadvantages: The liquid being measured contains a lot of impurities, which can easily block the pressure guiding pipe after long-term accumulation and require regular maintenance.

differential pressure submersible level gauge.

Advantages: Differential pressure liquid level measurement has no mechanical wear, reliable operation, stable quality, long service life, simple structure, convenient installation, convenient operation and maintenance, small size, and is suitable for most normal temperature and pressure situations.

Disadvantages: The liquid in the pressure tube is easily affected by temperature and requires heat tracing and insulation. It is very troublesome to put it into use. You need to fill the pressure pipe of the transmitter with water before it can be put into use accurately.