The selection of the pressure gauge should be based on the use requirements and specific analysis for specific situations. In compliance with the technical requirements put forward in the production process, the type, model, measurement range and accuracy level of the instrument should be reasonably selected in accordance with the principle of economy.
1) Selection of instrument type
The general principle for selecting instruments is to meet the requirements of the production process. In specific selection, three aspects can be considered: (1) the properties of the measured medium, such as the temperature and pressure, the size of the viscosity, the presence or absence of corrosion, the degree of dirt, and the flammable and explosive conditions; Requirements for display, such as general on-site instructions, or remote display signal alarm, data accumulation, or automatic recording; (3) Environmental conditions, such as the level of ambient temperature, the strength of electromagnetic fields, humidity, vibration, and corrosiveness And so on.
2) Determination of instrument measuring range
The measuring range of the meter should be determined according to the measured pressure. For the elastic pressure gauge, in order to ensure that the elastic element works reliably within the safe range of elastic deformation, when determining the measurement range of the pressure gauge, it must be paid enough attention. Generally, when the measured pressure is relatively stable, the maximum pressure value should not exceed 3/4 of the upper limit of the measurement of the instrument; when the measured pressure fluctuates greatly, the maximum pressure value should not exceed 2/3 of the upper limit of the instrument. In order to ensure the measurement accuracy, the minimum value of the measured pressure should not be less than 1/3 of the measuring range of the instrument.
According to the above principles, the upper and lower limits of the meter are initially calculated, but this cannot be used as the measuring range of the meter. Because the measuring range of the meter has been standardized and serialized by the national competent department and cannot be selected arbitrarily, the product manual should be consulted based on the calculated value to compare with the measuring range series of the stereotyped meter to determine the upper and lower limits of the corresponding meter measurement value.
3) Selection of instrument accuracy level
The accuracy of the instrument should be determined according to the maximum measurement error allowed in production. When selecting, you should choose a pressure gauge with low accuracy and low cost as much as possible while meeting the production requirements.