If a master meter is used to check vapor meters, how often must it be certified?

The correct answer indicates that a master meter used to check vapor meters must be certified every 2 years. Certification of a master meter is important for ensuring the accuracy and reliability of measurements taken by associated vapor meters. Regular certification helps to maintain compliance with industry standards and regulations, ensuring that the measurement system operates within the allowed tolerances for accuracy.

The 2-year timeframe reflects a balance between the need for precision in measurement and the practical constraints of resources and logistics involved in frequent calibrations. This schedule helps prevent any significant drift in measurement performance over time, which could lead to errors in the reporting of vapor flow rates.

In contrast, while other options suggest different intervals, they either do not align with established industry practices for meter certification or could lead to increased risk of measurement inaccuracies due to prolonged periods between certifications. The 2-year standard supports maintaining a high level of measurement integrity while not overburdening operations with excessively frequent checks.