With the development of science and technology and the promulgation of energy-saving and emission reduction policies, the measurement of DC power has been widely used in industrial production and scientific research experiments, and the measurement of DC power has important significance. Wide range of traffic and applications.
【9 notes on instrument technology selection】
1. Measurement range, necessary accuracy and measurement function: The minimum pressure measurement value is greater than 1/3 of the pressure gauge measurement, and remote measurement and measurement accuracy are required.
If the requirements are high, a pressure sensor or a differential pressure sensor should be selected; if measurement accuracy is not required, a resistive or electromechanical, Hall effect centrifugal pressure gauge can be selected; the movement of air is a pressure gauge.
Basic pressure indication regulator is suitable for local pressure indication adjustment.
2. The structure, shape, size of the container to be tested, the accessories in the container, and various input / output material nozzles must be considered: for example, towers, solution tanks, reactors, boiler drums, tanks, spherical tanks, etc.
3. The process selection must have a unified thinking: try to reduce the variety standards, reduce the number of fixtures, and conduct profit management.
4. The environment that the pressure gauge faces: For example, the industrial environment of the petrochemical industry, there is a flammable (toxic) explosion dangerous atmosphere, the ambient temperature is high, etc., the work of pressure sensors and pressure switches should be done well.
5. Reasonably select according to the detonation requirements of the installation site.
6. Actual process conditions: what equipment should be considered. For storage tanks and storage tanks, the storage tank volume is small, the measurement range is not large, and the storage tank volume is large, and the measurement range is possible.
7. According to the nature and cleanliness of the medium, choose a positive pressure difference sensor and a float-type liquid sensor to select the material that contacts the medium. The single flange differential pressure sensor can be used as a medium for floating objects and bubbles. There are some double-flange differential pressure sensors that are easy to deposit crystals.
8. The liquid level of the high-viscosity medium and the liquid level of the high-pressure device must not be perforated.
9. Other requirements, such as environmental protection and sanitation requirements, and specific requirements of process patents. Of course, in addition to measurement methods and technical issues, there are also problems with instrument investment. Physical and chemical properties and state of the tested medium: strong acid, strong alkali, high viscosity, easy to solidify. Changes in operating conditions: changes in medium temperature, pressure, and concentration. From operation to normal production, the concentration and density of the gas and liquid phases can be considered.