Why should the accuracy class of pressure gauge be 1.6 instead of 1.5?
The accuracy rating of the pressure gauge uses the R5 number system. In the past, 1.5 of the gauge grade did not belong to the R5 Coefficient, so it had to be abolished and replaced by 1.6, the closest approximation to 1.5. Therefore, it is no longer allowed to grade the pressure gauge to 1.5. Why should the accuracy rating of a general pressure gauge be 1.6 instead of 1.5? It is necessary to understand the basic knowledge of the Preferential Coefficient in the standardization technology. For the number system, the National Standard GB/T321 stipulates the “Priority number system”, which uses the common ratio of 10 to the power of 1/n, and has 10 to the power of 1/5,1/10,1/20,1/40,1/80 respectively, and the code names are R5, R10, R20, R40, R80 respectively. The accuracy rating of the pressure gauge is based on the R5 number system. The common ratio of the R 5 number system is: 10 to the 15th power = 1.60. Numbers in a number system include: 1.0,1.6,2.5,4.0,6.3, and 10. In the past, 1.5 of the gauge grade did not belong to the R5 Coefficient, so it had to be abolished and replaced by 1.6, the closest approximation to 1.5. Therefore, it is no longer allowed to grade the pressure gauge to 1.5. The ratio of two adjacent numbers is equal to the common ratio of the R 5 number system 1.6. For example: 10/6.3 = 1.6,6.3/4 = 1.6,4/2.5 = 1.6,2.5/1.6 = 1.6,1.6/1 = 1.6,0.63/0.4 = 1.6,0.4/0.25 = 1.6,0.25/0.16 = 1.6,0.25/0.16 = 1.6, ... Of course, if you do the inverse, you can also derive both sides of an accuracy level by rounding. For example, 2.5 is 1.6 = 1.6, and 2.5 × 1.6 = 4. Detailed knowledge of the number system can be found in the national standard.
What is the difference between accuracy class 1.6 and accuracy class 1.5? The accuracy grade of a pressure gauge is the percentage of the permissible error of the gauge to the full range. For example, if the full range of a pressure gauge is 100 MPA and the accuracy grade is 1.6, the permissible error of the gauge is 100 MPA × 1.6% = ± 1.6 MPA. If the accuracy is rated at 1.5, the permissible error is 100 MPA × 1.5% = ± 1.5 MPA. In normal use conditions, the accuracy of the instrument measurement results called the accuracy of the instrument. The smaller the reference error is, the higher the accuracy of the instrument is, and the reference error is related to the range of the instrument. In industrial measurement, in order to express the quality of the instrument conveniently, the accuracy level is usually used to express the accuracy of the instrument. The accuracy rating is the maximum citation error minus the plus, minus, and percent marks. Accuracy grade is one of the important indexes to evaluate the quality of instrument. In industrial measurement, the accuracy level is usually used to indicate the quality of instrument. The accuracy rating is the maximum citation error minus the plus, minus, and percent marks. Accuracy grade is one of the important indexes to evaluate the quality of instrument.
