First determine the maximum value of the measured pressure in the system. Generally speaking, you need to select a transmitter with a pressure range that is about 1.5 times larger than the maximum value, or let the normal pressure range fall on the pressure transmitter. 1/3~2/3 of the normal range is also a common method.
- What kind of pressure medium:
Viscous liquids and muds will block the pressure ports. Will solvents or corrosive substances destroy the materials in the transmitter that are in direct contact with these media.
The material of the general pressure transmitter that contacts the medium is 316 stainless steel. If the medium is not corrosive to 316 stainless steel, then basically all pressure transmitters are suitable for measuring the pressure of the medium;
If the medium is corrosive to 316 stainless steel, a chemical seal should be used, and indirect measurement should be used. If the capillary tube filled with silicone oil is used to guide pressure, it can prevent the pressure transmitter from corrosion and prolong the life of the pressure transmitter.
- How much accuracy the transmitter needs:
The accuracy is determined by: non-linearity, hysteresis, non-repeatability, temperature, zero offset scale, and temperature. The higher the accuracy, the higher the price. Generally, the accuracy of the diffused silicon pressure transmitter is 0.5 or 0.25, and the capacitive or monocrystalline silicon pressure transmitter has an accuracy of 0.1 or even 0.075.
- Process connection of transmitter:
Generally, pressure transmitters are installed on pipes or tanks. Of course, a small part of them are installed and used with flow meters. There are usually three installation forms of pressure transmitters: thread, flange, and clamp. Therefore, before selecting the pressure transmitter, the process connection must also be considered. If it is threaded, it is necessary to determine the thread specification. For flanges, it is necessary to consider the flange specifications of the nominal diameter.
Pressure transmitter industry introduction
About 40 countries around the world are engaged in the research and production of sensors, of which the United States, Japan, and Germany are the regions with the largest sensor output. The three countries together account for more than 50% of the world’s sensor market.
Nowadays, the pressure transmitter market in my country is a mature market with high market concentration. However, the dominant position is the foreign countries represented by Emerson, Yokogawa, Siemens, etc. Brand-name products account for about 70% of the market share and have an absolute advantage in large and medium-sized engineering projects.
This is due to the sequelae of my country’s early adoption of the “market for technology” strategy, which hit my country’s state-owned enterprises a great deal and was once in a state of failure, but at the same time, some manufacturers, represented by China’s private enterprises, quietly Appear and grow stronger. China’s future pressure transmitter market is full of new unknowns.
