The "new" code reduces mandatory steady-state hold times from 60 minutes to 30 minutes for digital systems, provided the plant load does not drift by more than 0.25% per hour. This allows testing to be completed in a single shift rather than two.

: Relies on fewer direct measurements and more correction curves. It is cheaper to execute but results in slightly higher uncertainty. Key "New" Related Updates Performance Test Codes - ASME

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Older versions relied on outdated statistical methods. The new ASME PTC 6 adopts modern uncertainty propagation techniques aligned with the ISO Guide to the Expression of Uncertainty in Measurement (GUM) . This allows engineers to identify dominant error sources in real-time.