The selection of the hydraulic pressure gauge should be based on the production requirements of the process, and specific analysis should be made for the specific situation. Under the premise of meeting the requirements of the process, it should be considered comprehensively and comprehensively in accordance with the principle of economy. Choosing the appropriate measuring range In order to ensure that the elastic component can work reliably within the safe range of elastic deformation, when selecting the gauge range, it must be based on The pressure is measured and the pressure changes, leaving enough room. Therefore, the upper limit of the pressure gauge should be higher than the maximum pressure possible in the process. According to the “Technical Regulations for Chemical Self-Control Design”, when measuring the steady pressure, the maximum working pressure of the press should not exceed 2/3 of the upper limit of measurement; when measuring the pulsating pressure, the maximum working pressure should not exceed 1/ of the upper limit of measurement. 2; When measuring high pressure, the maximum working pressure should not exceed 3/5 of the upper limit of measurement. Generally, the minimum value of the measured pressure should not be less than 1/3 of the upper limit of the meter measurement. Thereby ensuring the linear relationship between the output of the meter and the input volume. Improve the accuracy and sensitivity of the meter measurement results. The hydraulic press calculates the upper and lower limits of the meter according to the maximum and minimum values of the measured parameters, and cannot directly use this value as the measuring range of the meter. When selecting the upper limit of the scale of the instrument, we should select it in the standard series specified by the state.