Improper measurement range selection , and the always accuracy goes wrong?The Common Mistakes in Using Pressure Gauges Unveiled!

The following is the relevant knowledge about the "Accuracy" and "Measurement Range "of pressure gauges.                
                    
I.ACCURACY 
            
1.Definition                
The range of deviation between the measured value of the pressure gauge and the actual value is usually expressed as a percentage of the full scale.            
2.Grade                
Industrial Standard:1.0 grade , 1.6 grade,2.5 grade(Is usually used in China); 0.5 grade , 1.0 grade(High Accuracy)            
3.Measurement Error                
When the measurement range is 10MPa and the accuracy is 1.6 grade, the allowable error is ±10 MPa * 1.6% = ±0.16 MPa.            
4.Choice Suggestion                
According to the process requirements, for general industrial use, choose grade 1.6; for laboratories, aerospace (aircraft carriers), or petroleum and chemical applications, select grade 0.5.    

       
II.MEASUREMENT RANGE
1.Definition                
The maximum value that the pressure gauge can measure (such as 0 - 1 MPa, 0 - 6 MPa, 0 - 10 MPa...)            
2.Choice Principle                
Regular Usage: The working pressure should be between 1/3 and 2/3 of the range (For example, if the working pressure is 0.4 MPa, it is recommended to choose 0 - 0.06 MPa or 0 - 1 MPa).                        
3.Overload Risk                
Excessive use beyond the specified range for a long time will damage the instrument. The maximum allowable pressure is typically 130% of the range (Depending on the model).    

       
III.THE RELATIONSHIP BETWEEN ACCURACY AND MEASUREMENT RANGE
1.Error Correlation                 
For the same accuracy grade, a larger measurement range in a larger absolute error(A 1.6 garde pressure gauge ; At 10MPa range , error =±0.16MPa. At 100MPa range , error =±1.6MPa).            
2.Economical                 
High-Accuracy instruments incurhigher costs ,necessitating careful trade-off analysis.            
Example for measuring 0.5MPa pressure :                
Eelect a 0~0.6MPa range gauge (1.6 grade)   Error =±0.0096MPa                
Eelect a 0~10MPa range gauge (1.6 grade)   Error =±0.16MPa (Didn't recommend )      

     
IV.OTHER INFLUENCING FACTORS 
1.Ambient Temperature                
Temperature variations may introduce additional errors (such as 0.4% per 10℃)            
2.Media Characteristics                
Corrosive, viscous and particulate media require the use of specialized materials(Such as 316/316L gauges ,diaphragm gauges).            
3.Installation                 
Direct installation, threaded installation or flange installation may all affect the actual accuracy.    

           
SUMMARIZ
When selecting a pressure gauge, it is necessary to consider the actual pressure range, accuracy requirements, and medium conditions comprehensively. Prioritize ensuring that the working pressure is within the 1/3 to 2/3 range of the measurement range, and select an appropriate accuracy to achieve the best cost-performance ratio.