4. The measurements and quantification referred to in paragraphs 1, 2 and 3 shall be undertaken in accordance with the applicable standards or technical prescriptions established pursuant to Article 32. Until the date of application of those standards or technical prescriptions, mine operators shall follow state-of-the-art industry practices and use the best available technologies for the measurement and quantification of methane emissions. Mine operators shall provide competent authorities and verifiers with information on the standards, including international standards, or methodologies used.
As regards continuous source-level direct measurements and quantification referred to in paragraphs 1 and 2, where part of the measuring equipment is not operating for a certain period, readings taken during periods when the equipment was operating may be used to estimate data on a pro rata basis for the period that the equipment was not operating.
The equipment used for continuous source-level direct measurements and quantification referred to in paragraphs 1 and 2 shall operate for more than 90 % of the period for which it is used to monitor methane emissions, excluding downtime taken for re-calibration and repairs.