What are the Class A measurement requirements for trade handover measurements of flowmeters?

High precision and good stability; used as a flow meter for measurement.

Regulations on the Classification and Management of Measuring Instruments I. Measuring instruments are classified into three grades: A, B, and C. 1. Scope of management for Grade A 1.1. The highest standard instruments in enterprises and institutions. 1.2. Social public measurement standards certified and authorized by the **measurement administration department. 1.3. Measuring instruments specified in the Metrology Law that are subject to mandatory inspection for use in trade settlement, safety protection, environmental monitoring, and healthcare. 1.4. Reference materials for unified measurement values. 2. Scope of Class B management 2.1. Working standard measuring instruments used for value transfer. 2.2. Measuring instruments with control circuits and important monitoring parameters used in the production process, or measuring instruments for monitoring key parameters during construction. 2.3. Measuring instruments used for internal economic accounting and material management in enterprises. 2.4. Main measuring instruments used in product quality inspection. 2.5. Measuring instruments installed on production lines or equipment, which require high accuracy in measuring data and cannot be removed without shutting down the operation. 3. Scope of Class C management 3.1. Measuring instruments used in non-critical areas of the production process, for which no accuracy requirements apply and that serve only as indicators. 3.2. Measuring instruments with low requirements for accuracy of measurement data, low usage frequency, and stable performance. 3.3. Use measuring instruments that are designed for harsh operating conditions, have a short lifespan, are low-cost and expendable, do not require high accuracy, or are custom-made specialized instruments. 3.4. Low-value, fragile measuring instruments for non-critical items in the inspection of production processes. 3.5. Measuring instruments used as tools. 3.6. Household measuring instruments for daily use and measuring instruments for the welfare of frontline employees. 3.7. Indicating instruments and panel-mounted devices that are integral to the complete set of equipment and cannot be removed

II. Management Measures for the Classification of Measuring Instruments A, B, and C 1. Management Measures for Class A Measuring Instruments 1.1. All measuring instruments falling under the category of Class A must apply to the **metrology administrative department for calibration in accordance with the requirements of the **calibration regulations. For enterprises that are authorized by the **metrology administrative department to conduct self-inspections, inspections should also be arranged in strict accordance with the requirements of the **verification procedures. 1.2. For measuring instruments for which there are no established calibration procedures, enterprises shall develop their own methods for calibration or comparison in accordance with **relevant regulations, and submit them to the local metrology administrative authority for record-keeping. 1.3. Units that use measuring instruments subject to mandatory verification shall assign full-time or part-time personnel to manage them, to ensure that periodic verifications are carried out in strict accordance with the regulations, and to supervise and inspect their usage. 1.4. The units that use reference materials should be strictly stored and handled. 2. Management Measures for Class B Measuring Instruments 2.1. For measuring instruments that cannot be removed from continuously operating devices, in accordance with relevant calibration regulations, their calibration intervals can be scheduled in line with the equipment’s maintenance cycle; however, strict supervision and inspection are required during normal operation. 2.2. For measuring instruments with high accuracy requirements but stable performance that are not used frequently, the calibration interval can be appropriately extended. The extended time should be based on the principle of ensuring the reliability of the measuring instruments. For measuring instruments that are used frequently and for which accuracy is essential, the calibration interval should be shortened as appropriate. 2.3. When general measuring instruments are used for specific purposes, the number of inspection items can be appropriately reduced or only partial inspections carried out, in accordance with the actual usage requirements and the provisions of the calibration regulations. However, the calibration certificate must indicate the permitted range of use and location, and a restriction label must be attached in a visible place on the measuring instrument. 2.4. For measuring instruments for which no verification procedures are available, the provisions of clause 1.2 shall be applied. 3. Management Measures for Class C Measuring Instruments 3.1. For those measuring instruments that require no high level of accuracy, whose performance is not prone to change, and that are used as low-value consumables or tools, a one-time calibration may be sufficient. 3.2. Measurement instruments that serve as indicators in non-critical areas, are used infrequently, have stable and durable performance, and are installed permanently on continuously operating equipment can be subject to a validity period management system, or their calibration intervals can be extended, generally to between 2 and 4 intervals. 3.3. For measuring instruments for which no calibration procedures are available, the provisions of clause 1.2 shall be followed. 3.4. Measuring instruments intended for domestic welfare are strictly prohibited from being used in production and other fields. 3.5. For the remaining measuring instruments classified under Category C, supervisory management can be implemented based on their type and usage patterns.

The last edit to this post was made by zzllyp on 2018-10-19 at 09:47. Grading is primarily reflected in inspection and management; no precision requirements exist. For precision details, refer to the \"General Rules for the Provision and Management of Energy Measurement Instruments in Energy-Using Units.\" When placing an order, it is necessary for the supplier to provide an inspection certificate from a qualified institution or results from an inspection conducted by the local metrology department

In short, for grade A, choose ones with high precision – never skimp on costs just to save money!