Chinese
Precision digital pressure gauges serve as standard instruments, primarily used for calibrating pointer pressure gauges, digital display pressure gauges, and other similar products. So, how is a digital pressure gauge calibrated?
The calibration of a digital pressure gauge refers to the standard "JJG875-2005 Verification Regulation for Digital Pressure Gauges." According to this regulation, the following conditions must be met before calibration can begin:
◆ Ambient Temperature: 20 ± 2°C
◆ Relative Humidity: Not more than 85%
◆ Selection of Standard Pressure Gauge: The measurement range of the standard instrument should be greater than or equal to that of the digital pressure gauge under test. The maximum permissible error absolute value of the standard must be less than 1/3 of the maximum permissible error absolute value of the gauge being calibrated. For pressure gauges of class 0.05 (including 0.05) and above, when using a piston pressure gauge as the standard, the maximum permissible error absolute value of the standard must be less than 1/2 of the maximum permissible error absolute value of the gauge under test.
The main calibration items include: Maximum Permissible Error, Hysteresis Error, Zero Drift, and Stability.
1.Accuracy Class & Maximum Permissible Error: The accuracy classes and their corresponding maximum permissible errors are 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 1.0, and 1.6.
2.Hysteresis Error: The hysteresis error must not exceed the absolute value of the maximum permissible error.
3.Zero Drift: The zero drift of a precision digital pressure gauge within one hour must not exceed 1/2 of the absolute value of its maximum permissible error.
4.Stability: The indication change between two consecutive calibration cycles must not exceed the absolute value of the maximum permissible error.