JJG 154-2012 in English

Key points of the revision of the regulations

Key metrological characteristics of viscometer

Calculate the viscometer constant according to the formula C=ν/t:

• The inner diameter of the capillary is divided into 8 grades (0.45-6.9mm)
• Time repeatability requirement ≤0.2%
• Constant reproducibility ≤0.3%

Verification operation specifications

Selection of standard materials

It is necessary to use National first-level standard viscosity fluid, and the viscosity range corresponding to different inner diameters is:

• 0.45mm capillary: 2mm²/s (double batch number)
• 6.9mm capillary: 30000-40000mm²/s

Constant temperature control requirements

Implementation suggestions

Abnormal handling process

1. Single out-of-tolerance data: take the average of 5 times after elimination
2. Double out-of-tolerance data: need to be cleaned and re-calibrated
3. Stability exceeds the standard: re-inspect after traceability analysis

Maintenance points

Cleaning must meet the standard of no water droplets on the inner wall, and the drying temperature shall not exceed 120℃. Recommendations for high-precision measurements:

• 0.45mm capillary: outflow time ≥ 600s
• Establish a 4-year period stability profile