1. Development of Pressure Gauge Calibration Requirements
01 Development of calibration requirements for pressure gauges
The requirement for mandatory verification of measuring instruments was introduced when the Metrology Law of the People's Republic of China was promulgated in 1985. The initial list of working measuring instruments subject to mandatory verification (which included pressure gauges) was first published in 1987 in the Measures for the Administration of Verification of Working Measuring Instruments Subject to Mandatory Verification of the People's Republic of China.
Since the first publication of the mandatory verification list, it has been adjusted seven times over 25 years. The scope of mandatory verification for pressure gauges changed from an initial three categories (pressure gauge, wind pressure gauge, oxygen pressure gauge) and ten types (first specified in 1991) to a single category covering six types of pressure gauges.
The following documents and related requirements issued by national metrology and verification authorities are relevant to these changes:
Metrology Law and early measures
Metrology Law of the People's Republic of China (Promulgated by Presidential Decree No. 28 on September 6, 1985; effective July 1, 1986)
Article 9: The metrology administrative department of the people's government at or above the county level shall implement mandatory verification for public metrological standards, the highest metrological standards used by departments and enterprises, and working measuring instruments included in the mandatory verification list that are used for trade settlement, safety protection, medical and health services, and environmental monitoring. Instruments for which verification is not applied for as required or that fail verification shall not be used. The mandatory verification list and its administration methods shall be formulated by the State Council.
For other metrological standards and working measuring instruments not covered by the preceding paragraph, the user unit shall carry out regular verification by itself or send them to other metrological verification institutions for verification.
Measures for the Administration of Verification of Working Measuring Instruments Subject to Mandatory Verification
Measures for the Administration of Verification of Working Measuring Instruments Subject to Mandatory Verification (State-issued [1987] No. 31; effective July 1, 1987)
Article 1: These measures were formulated to strengthen management of working measuring instruments subject to mandatory verification in order to meet modernization needs and protect national and consumer interests, health, and property, in accordance with Article 9 of the Metrology Law.
Article 16: The metrology administrative department under the State Council may, according to these measures and the Mandatory Verification List of Working Measuring Instruments, formulate a detailed list of working measuring instruments subject to mandatory verification.
Attachment: Mandatory Verification List of Working Measuring Instruments of the People's Republic of China. The list contained 55 items, with item 25 covering pressure gauges.
Detailed list and 1991 provisions
Detailed List of Working Measuring Instruments Subject to Mandatory Verification (National Metrology Bureau, [1987] No. 188; effective July 1, 1987)
Pressure gauges were divided into three categories: pressure gauges, wind pressure gauges, and oxygen pressure gauges.
Notice on Issuing the Provisions on the Implementation of Verification for Working Measuring Instruments Subject to Mandatory Verification (Trial) (Technical Supervision Bureau Document, [1991] No. 374)
Subsequent adjustments and product classifications
1999 and 2001 adjustments to the mandatory verification list did not affect the pressure gauge items.
2002 removal of vehicle odometers from the mandatory verification list did not affect pressure gauges.
Catalogue of Measuring Instruments Administered According to Law (Type Approval Part) (General Administration of Quality Supervision, Inspection and Quarantine Announcement [2005] No. 145; effective May 1, 2006)
The attachment listed 75 categories requiring measurement instrument licensing, type approval, and import verification. Categories 24 and 25 covered pressure instruments and pressure transmitters/pressure sensors.
Pressure instruments included: Bourdon tube precision pressure gauges and vacuum gauges, Bourdon tube general pressure gauges, pressure-vacuum gauges and vacuum gauges, capsule pressure gauges, recording pressure gauges, tire pressure gauges, pressure controllers, digital pressure gauges.
Pressure transmitters and pressure sensors included pressure transmitters and pressure sensors.
Announcement on Issuing the Import Type Examination Catalogue for Measuring Instruments (General Administration of Quality Supervision, Inspection and Quarantine Announcement [2006] No. 5; effective August 1, 2006)
This document required that measuring instruments not included in the new catalogue would no longer undergo import type approval. The attachment listed over 220 types across 75 categories requiring import type approval, including the same pressure instrument categories described above.
2019 and 2020 regulatory announcements
Announcement on the Catalogue of Measuring Instruments Subject to Mandatory Management (State Administration for Market Regulation Announcement [2019] No. 48)
From the date of this announcement, instruments listed with regulatory mode V (mandatory verification) or P+V (type approval + mandatory verification) must undergo mandatory verification during use. Instruments not listed no longer require mandatory verification; users may choose non-mandatory verification or calibration to ensure measurement accuracy.
Several earlier documents were repealed by this announcement, including the 2005 type approval catalogue, the 2006 import type examination catalogue, and earlier detailed lists and notices related to mandatory verification.
Announcement on Adjusting the Catalogue of Measuring Instruments Subject to Mandatory Management (State Administration for Market Regulation Announcement [2020] No. 42)
Compared with Announcement No. 48, the regulatory mode for pressure instruments did not change, but the mandatory verification scope removed pressure transmitters and pressure sensors. Compared with the 1991 provisions, the mandatory verification scope removed pressure gauges used for measurements of medical high-pressure sterilizers and high-pressure furnaces, as well as wind pressure gauges and oxygen pressure gauges.
2. Graded management requirements for pressure gauges
Pressure gauges are measuring instruments. According to the Measures for Graded Management of Measuring Instruments in the Chemical Industry (Trial), pressure gauges used in chemical enterprises should be managed by grade A, B, or C. The management scope for each grade is as follows:
- Grade A: 1. The unit's highest standard pressure instruments. 2. Pressure gauges used for safety protection as defined in the Metrology Law.
- Grade B: 1. Pressure gauges used in production processes with control loops and important measurement parameters or in construction for measuring process parameters. 2. Pressure gauges installed on production lines or equipment with high accuracy requirements but that cannot be removed without stopping production.
- Grade C: 1. Pressure gauges used in noncritical parts of production with no accuracy requirement, serving only as indicators. 2. Indicating instruments and panel-mounted instruments that cannot be disassembled from complete equipment.
The Measures for Graded Management of Measuring Instruments in the Chemical Industry (Trial) (Ministry of Chemical Industry and Technical Supervision Bureau [1988] No. 806) specifies:
- Article 3: Measuring instruments shall be managed in three grades: A, B, C.
- Article 4: Grade A scope includes highest standards of enterprises and institutions, government-authorized public metrological standards, instruments subject to mandatory verification under the Metrology Law for trade settlement, safety protection, environmental monitoring, and medical and health use, and certified standard reference materials.
- Article 5: Grade B scope includes working standard measuring instruments for value transfer, instruments used in production processes with control loops and important parameters, instruments used for internal economic accounting and material management, main measuring instruments in product quality inspection, and instruments on production lines or equipment that require high accuracy but cannot be removed without stopping production.
- Article 6: Grade C scope includes instruments used in noncritical production parts with no strict accuracy requirements, low-frequency and stable instruments, disposable or short-life instruments used in harsh environments without strict accuracy requirements, and low-value consumable instruments.
Article 7 to 9 specify management measures for each grade:
- Grade A: Instruments must be verified according to national verification procedures by government metrology departments; units must assign personnel to manage them; if no national procedure exists, units should develop calibration or comparison methods and file them with local metrology authorities.
- Grade B: For instruments on continuously operating equipment that are difficult to remove, verification can be synchronized with equipment overhaul cycles; verification intervals may be extended for stable, infrequently used high-accuracy instruments, provided reliability is ensured; verification items may be reduced for general instruments used for special purposes, with limitations recorded on the verification certificate and on the instrument.
- Grade C: Low-value, consumable, or tool-type instruments may undergo one-time verification; noncritical indicating instruments or instruments on continuously operating equipment may be managed by validity period or have extended verification intervals, generally controlled within 2-4 cycles; some C-grade instruments may be subject to supervision-only management.
Article 13: Grades A and B instruments must have corresponding verification certificates and original verification records. Grade C should have original verification records or product conformity certificates bearing type approval marks. Note: Since the cancellation of the manufacturing and repair licensing for measuring instruments, CMC marking is no longer required; however, CPA type approval marking for measuring instruments remains applicable.
3. Verification requirements for pressure gauges
Verification of pressure gauges is divided into mandatory verification and non-mandatory verification. Grade A pressure gauges fall under mandatory verification. Grade B and C pressure gauges are generally non-mandatory; B-grade gauges should undergo periodic verification, while C-grade gauges may be assigned periodic verification, pre-use verification, one-time verification after failure, or no verification (replaced upon failure), depending on their specific use.
Specific verification requirements by grade:
- Grade A: 1. The unit's highest standard pressure instruments: verification interval generally does not exceed one year. 2. Pressure gauges used for safety protection under the Metrology Law: verification interval generally does not exceed six months.
- Grade B: 1. In chemical production enterprises, pressure gauges used for process control: verification interval aligns with equipment overhaul periods. 2. In chemical construction enterprises, pressure gauges used to measure major parameters during construction: verification interval is 12 months.
- Grade C: 1. In chemical production enterprises, pressure gauges used for monitoring: verification interval is generally 1 to 2 overhaul cycles. 2. Monitoring pressure gauges that do not require verification: replaced upon single failure. 3. In chemical construction enterprises, monitoring pressure gauges and oxygen/acetylene gauges: one-time verification and repair upon failure. 4. In construction enterprises, pressure gauges used for pre-use pressure testing: verify before use.
Verification requirements are based on national laws, regulations, departmental rules, and technical verification regulations, summarized below.
Key legal and technical references
01/ Metrology Law of the People's Republic of China (2018 revision)
Article 9: The metrology administrative department at or above the county level shall implement mandatory verification for public metrological standards, highest metrological standards used by departments and enterprises, and working measuring instruments included in the mandatory verification list that are used for trade settlement, safety protection, medical and health services, and environmental monitoring. Instruments for which verification is not applied for as required or that fail verification shall not be used. The mandatory verification list and its administration methods shall be formulated by the State Council.
Article 10: Metrological verification must follow the national metrological verification system table and the national verification regulations formulated by the metrology administrative department under the State Council. If a national verification regulation does not exist, the competent national department and provincial metrology departments should separately establish departmental or local verification regulations.
02/ Implementation Rules of the Metrology Law of the People's Republic of China (2018 revision)
Article 11: Units and individuals using standards subject to mandatory verification must apply to the relevant metrology administrative department for periodic verification. Units and individuals using working measuring instruments subject to mandatory verification must apply to designated verification institutions appointed by local county-level metrology administrative departments. If local verification cannot be performed, application should be made to institutions designated by the next higher-level metrology administrative department.
Article 12: Enterprises and institutions should be equipped with measurement and testing facilities appropriate to their production, research, and management needs, formulate specific verification management methods and rules, and specify detailed inventories of instruments and corresponding verification intervals to ensure non-mandatory instruments are regularly verified.
03/ Measures for Graded Management of Measuring Instruments in the Chemical Industry (Trial), Ministry of Chemical Industry and Technical Supervision Bureau, 1988
Article 7 to 9: Management methods for A, B, and C grade instruments are defined, including requirements for verification, record keeping, and supervision. A and B grade instruments must have verification certificates and original verification records. C grade instruments must have original verification records or conformity certificates bearing type approval marks as appropriate.
Appendix 1 provides graded management directories for chemical production enterprises, listing A, B, and C grade instruments related to pressure gauges. Separate appendices provide graded directories for chemical construction enterprises.
Verification cycle provisions in national verification regulations
04/ Announcement on Adjusting the Catalogue of Measuring Instruments Subject to Mandatory Management (SAMR Announcement [2020] No. 42)
Mandatory verification cycles are determined by the relevant verification procedures. If verification cycles are revised in those procedures, the revised cycles apply.
05/ National Verification Regulation "Precision Elastic Element Pressure Gauges and Vacuum Gauges" JJG49-2013
Section 7.5 Verification interval: The verification interval for precision gauges may be determined based on the use environment and frequency; generally not exceeding one year.
06/ National Verification Regulation "General Spring Element Pressure Gauges, Pressure-Vacuum Gauges and Vacuum Gauges" JJG52-2013
Section 7.5 Verification interval: The verification interval for pressure gauges may be determined based on the use environment and frequency; generally not exceeding six months.
07/ National Verification Regulation "Digital Pressure Gauge" JJG875-2019
Section 7.5 Verification interval: The verification interval may be determined based on environment, frequency of use, and working requirements; generally not exceeding one year. For digital pressure gauges failing stability checks, the verification interval should be shortened to six months.
