The testing of SF6 density monitors for digital remote transmission meters by CEPRI typically involves checking the accuracy and reliability of the monitor in measuring the density of SF6 gas in high voltage equipment such as circuit breakers.

The testing process may include:

1. Verification of the monitor's calibration: The SF6 density monitor is calibrated to ensure that it provides accurate readings of the gas density. Testing involves comparing the monitor readings with a known reference standard to verify its accuracy.

2. Functional testing: The monitor is tested to ensure that it functions properly, including checking the display unit, alarm system, and remote transmission capabilities.

3. Performance testing: The monitor is tested under various operating conditions to assess its performance and reliability in measuring SF6 gas density accurately.

4. Endurance testing: The monitor may undergo endurance testing to evaluate its long-term performance and reliability under continuous operation.

CEPRI (China Electric Power Research Institute) is a research and development institution in China that specializes in power system technology. Their testing procedures for SF6 gas density monitors may vary depending on their specific requirements and standards. It is essential to follow their guidelines and recommendations for accurate and reliable testing of SF6 density monitors.