的应用选型一般是根据它的用途来定型的，其他的根据七个要点来选，分别是接液材质、精度、量程、输出信号、介质温度、测量介质，防爆等级 The application selection of pressure transmitter is generally determined according to its use. The other selection is based on seven points, which are the wetted material, accuracy, range, output signal, medium temperature, measurement medium, and explosion-proof level.
都适合你对介质压力的测量。 I. Wetted material: We need to consider the medium measured by the pressure transmitter. The material of the contact medium part of the general pressure transmitter is 316 stainless steel. If your medium is not corrosive to 316 stainless steel, then Basically all pressure transmitters are suitable for your measurement of medium pressure. If your medium is corrosive to 316 stainless steel, then we need to use chemical seals, which not only can measure the pressure of the medium, but also effectively prevent the medium from coming into contact with the wetted part of the pressure transmitter. Protect the pressure transmitter and extend the life of the pressure transmitter. 2.Accuracy level: Every electronic meter will have accuracy error, but the accuracy level marked by each country is different.For example, the national standard accuracy of China and the United States is the best linearity of the sensor. That is, what we usually call the accuracy between 10% and 90% of the measurement range; and the accuracy of the European standard is the worst part of linearity, which is what we usually call the inverse measurement of 0 to 10% and Accuracy between 90% and 100%. If the accuracy of the European standard is 1%, the accuracy of the Chinese standard is 0.5%. The accuracy level of the pressure transmitter developed by Shanghai Yongwei Automatic Control Equipment Co., Ltd. is 0.2. 3.Range range: The maximum range of the general sensor measurement is 70% of the sensor's full range, which is to measure the pressure of 70bar now, and the range of the pressure transmitter we choose should be 100bar. 4.Output signal: Currently Due to various acquisition needs, there are many output signals of pressure transmitters on the market today, mainly 4 ~ 20mA, 0 ~ 20mA, 0 ~ 10V, 0 ~ 5V, etc., but the more commonly used are 4 ~ 20mA and 0 There are two kinds of ~ 10V. Among these output signals I mentioned above, only 4 ~ 20mA is a two-wire system (the output we are talking about is a few-wire system without ground or shielded wires), and the others are three-wire systems. V. Medium temperature: Since the signal of the pressure transmitter is partially converted by the electronic circuit, in general, the temperature of the measuring medium of the pressure transmitter is -30 to +100 degrees. It is a condensate bend to cool the medium, so that the cost of producing a high temperature pressure transmitter for the manufacturer will be greatly reduced compared to the manufacturer. Measurement medium: Generally, we measure relatively clean fluids. We can directly use standard pressure transmitters. If the medium you are measuring is easy to crystallize or thick, we generally use An external diaphragm or a chemical seal is used together, which will effectively prevent the medium from blocking the pressure measurement hole. 7.Others: After we determine the above five parameters, we also need to confirm the process connection interface of your pressure transmitter and the power supply voltage of the pressure transmitter; if you use it in special occasions, you must also consider explosion-proof and protection levels.
六大使用注意事项 Six precautions for using pressure transmitters
1: Do not apply a voltage higher than 36V to the transmitter, causing damage to the transmitter; 2: Do not touch the diaphragm with a hard object, resulting in damage to the isolation diaphragm; 3: The measured medium is not allowed to freeze Otherwise, the sensor element isolation diaphragm will be damaged, resulting in damage to the transmitter. If necessary, the transmitter must be temperature protected to prevent freezing; 4: When measuring steam or other high-temperature media, its temperature should not exceed the transmitter. The limit temperature during use must be higher than the limit temperature used by the transmitter. 5: When measuring steam or other high-temperature media, a heat pipe should be used to connect the transmitter and the pipe together. The pressure is transmitted to the transformer. When the measured medium is water vapor, an appropriate amount of water must be injected into the heat pipe to prevent the superheated steam from directly contacting the transmitter and damaging the sensor. 6: During the pressure transmission process, the following points should be paid attention to: a. At the connection between the radiator and the heat pipe, do not leak air; b. Before starting to use, if the valve is closed, when using it, you should open the valve very carefully and slowly to prevent the measured medium from directly hitting the sensor diaphragm and damaging the sensor. Diaphragm; c. The pipeline must be kept clear, and the sediment in the pipeline will pop up and damage the sensor diaphragm;