Accuracy grade and selection of shockproof pressure gauge

Shock-resistant pressure gauge: A mechanical pointer pressure gauge with a filling fluid in the case, or a mechanical pointer (or rotary dial) pressure gauge with a filling fluid in the case and a damper is collectively referred to as a shock-resistant pressure gauge. Accuracy grade: The accuracy grade of the shock-resistant pressure gauge reflects how close the indicated value is to the real value when the tested meter is compared with the standard device. The accuracy level of the shock-resistant pressure gauge = the basic error value of the tested meter ÷ the ratio of the upper limit of measurement × 100%. The accuracy grades of shock-resistant pressure gauges are divided into: 1.0 grade; 1.6 grade; 2.5 grade; 4.0 grade; the nominal diameter of the shell of each grade of instrument should meet the requirements of the following table: the nominal diameter of the shell (mm) accuracy Grades 40; 50; 60; 752.5; 4.01001.6; 2.5150; 200; 2501.0; 1.6 The precision grades, allowable errors and their relations of shock-resistant pressure gauges are shown in the following table 2 Table 2 precision grades Permissible error % (calculated as a percentage of the range) (90~100)% of the upper limit of zero position measurement The rest with stop pin without stop pin 1.01±1±1.6±11.6(1.5)1. 6±1.6±2.5±1.62.52.5±2.5±4±2.54.04±4±4±4 Note: The allowable error of the 1.5-grade pressure gauge in use is calculated according to the 1.6-grade pressure gauge , the accuracy level may not be changed. Selection of accuracy grade: Method for selecting the accuracy grade of the pressure gauge: The accuracy grade should be determined according to the allowable error required by the minimum value of the measured pressure according to the requirements of the production process, economy and practicality, and testing methods. Generally speaking, the more precise the instrument selected, the more accurate and reliable the measurement result will be. But it cannot be considered that the higher the accuracy of the selected instrument, the better. Because the more precise the instrument is generally the more expensive it is, and the more troublesome it is to operate and maintain. Therefore, on the premise of meeting the process requirements, instruments with low precision, cheap and durable should be selected as much as possible. For example: the normal working pressure of a system is 15MPa, and the measurement error is required to be no more than plus or minus 0.3MPa. How to choose the accuracy grade and range of earthquake-resistant pressure gauge? Answer: The normal working pressure of the system is 15MPa, and the range of the shock-resistant pressure gauge is 0-25Mpa; The accuracy of the 25Mpa range meter is 1.2 grades, and the accuracy after correction is 1.0 grades