Regarding the classification of petrochemical measuring instruments, may I ask what qualifies as first-class measuring instruments and what qualifies as second-class measuring instruments?

Meters generally used for trade transactions between a company and external parties are classified as grade 1, while those used for internal measurement within the company are classified as grade 2

Classification and management of measuring equipment into categories A, B, and C: 4.2.1 Scope of Category A measuring equipment a. The company’s measurement standards used for value traceability, along with the accompanying measuring equipment, including reference materials that provide uniform values； b. Working measuring instruments that are subject to mandatory inspection and are used in areas such as trade settlement, security protection, environmental monitoring, and healthcare ； c. Key measuring equipment with high requirements for measurement data in process control, quality inspection, energy management, and business operations ； d. Measurement devices with high accuracy requirements but poor stability. 4.2.2 Scope of Class B measuring equipment: a. Measuring equipment used for energy and material management purposes in the company’s internal financial accounting ； b. Measurement equipment used for the control of the company’s production processes and for quality inspection, where measurement data is required ； c. Measurement devices with stable performance, whose indicated values do not change easily and are used infrequently ； d. Measurement devices that are fixedly installed on production lines or equipment, which require high precision in measurement data; they cannot be disassembled or assembled during production, and their calibration intervals must be synchronized with the equipment maintenance schedule. 4.2.3 Scope of Class C measuring equipment a. **Measuring equipment that is explicitly permitted for single-use or subject to a validity period management ； b. Measurement devices with very stable performance, low accuracy, and values that are not prone to change ； c. Indicating measuring equipment that is fixedly installed on assembly lines and devices by our company for use in production processes, quality inspection, and business management; such equipment is not easy to remove and does not require high accuracy ； d. Measurement equipment used in harsh environments, with short lifespans and low value as consumables, as well as self-made specialized measurement devices used as general tools for which no strict accuracy requirements apply.