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Specific regulations for measuring instruments by category

By Yasmine EDDAM30 April 2025

The regulations governing measuring instruments are not limited to a general framework. They are broken down into specific provisions adapted to the different categories of instruments, taking into account their particular technical features and uses. This sector-based approach ensures the accuracy of measurements in fields as varied as commerce, industry, health and the environment. For professionals using these instruments, understanding the requirements specific to their sector of activity is essential to guarantee legal compliance and avoid the penalties mentioned in our article on penalties for non-compliant instruments.

Instruments for measuring length and time

Length measurement and planimetric machines

Length measurements are among the oldest and most fundamental in our metrological system. Their regulation is based mainly on decree no. 75-906 of 16 September 1975, supplemented by various technical decrees.

These texts define the metrological characteristics that these instruments must have: accuracy, reproducibility, stability over time. They also specify the inspection procedures specific to this category.

For planimetric machines, used in particular to measure surfaces, decree no. 72-390 of 4 May 1972 establishes the regulatory framework. These instruments are particularly important in architecture, town planning and the textile industry, where the accuracy of surface measurements is crucial.

Manufacturers' obligations include obtaining a type examination certificate and undergoing initial verification. For users, periodic inspection is generally compulsory, with intervals defined by ministerial decree according to the specific category of instrument.

Taximeters and tachographs

Instruments for measuring time and speed are subject to particularly strict regulations, because of their economic and safety implications.

Taximeters, governed by decree no. 78-363 of 13 March 1978, as amended several times, are subject to precise requirements in terms of construction, model approval, installation and inspection. The decree of 18 July 2001 on taximeters in service sets out the procedures for periodic inspection, which is generally carried out annually.

Tachographs, which are used in road transport to record driving and rest times, as well as speed, are subject to European Regulation 3821/85/EEC of 20 December 1985, which has been amended several times, in particular by Regulation 2135/98/EEC, which introduced the digital tachograph.

Under national law, decree no. 81-883 of 14 September 1981 sets out the inspection procedures. These instruments must be periodically checked every two years, and calibrated after any operation likely to affect their accuracy.

The legislation also provides for specific penalties in the event of fraud. Law 95-96 of 1 February 1995 increases the penalties for fraudulent manipulation of tachographs, reflecting the importance of these instruments for road safety and regulation of the transport sector.

Weighing and volume measurement instruments

Automatic and non-automatic weighing instruments

Weighing instruments are a fundamental category, used in almost all sectors of the economy. Regulations distinguish between automatic and non-automatic weighing instruments.

For non-automatic weighing instruments (NAWIs), such as commercial scales or industrial weighing machines, European Directive 2009/23/EC, transposed into French law, provides the reference framework. Decree no. 65-487 of 18 June 1965, which has been amended several times, and the Order of 26 May 2004 govern the national aspects of the inspection of these instruments.

NAWIs are subject to type examination, initial verification and periodic verification. The frequency of the latter varies according to the use of the instrument: generally annual for commercial scales, biennial for certain industrial instruments.

The Order of 10 January 2006 specifies the inspection procedures for automatic weighing instruments (checkweighers, weighfeeders, etc.). These instruments are particularly common in the food and pharmaceutical industries, where they have to meet stringent accuracy requirements, as explained in detail in our analysis of the control of measuring instruments.

Water meters and measuring containers

Instruments for measuring volumes are subject to specific regulations, adapted to their technical characteristics and uses.

Cold water meters are governed by Decree no. 76-130 of 29 January 1976 and the Order of 6 March 2007 on in-service inspection. These texts require periodic inspection, the frequency of which varies according to the nominal flow rate and the type of meter.

Decree no. 82-537 of 22 June 1982 applies to hot water meters. Periodic inspection is also compulsory, with technical adaptations to take account of the particular constraints of hot water metering.

Measuring containers, used in particular for transporting and storing liquids, are subject to special rules. Decree no. 73-790 of 4 August 1973 regulates ship tanks, while decree no. 76-172 of 12 February 1976 covers containers, road or rail transport tanks, vats and storage tanks.

For these instruments, initial gauging and periodic checks are carried out in accordance with specific procedures detailed in the implementing decrees. The Order of 8 July 2003 on the metrological inspection of measuring vessels sets out the practical procedures for this inspection.

Energy measurement instruments

Electricity and gas meters

Energy measurement instruments are at the heart of major economic issues, which explains the rigour of their regulatory framework.

Electricity meters are governed by a decree dated 28 December 1935, which has been amended several times. These instruments must undergo a type examination and initial inspection. For meters in service, periodic inspections are required, the frequency of which may vary depending on the meter's technical characteristics and use.

European Directive 2004/22/EC on measuring instruments (MID), transposed into French law by Decree no. 2006-447 of 12 April 2006, introduced harmonised requirements for electricity meters placed on the market after its entry into force.

The Order of 21 October 2010 sets out the applicable rules for fuel gas meters. These meters must also comply with an approved type and undergo initial inspection. Periodic inspections are compulsory, with the frequency depending on the flow rate of the meter.

Work on these instruments is strictly regulated and must be carried out by approved professionals with the necessary technical skills who comply with regulatory procedures.

Heat meters

Heat meters, used in particular to measure heating consumption in apartment blocks, are subject to Decree no. 76-1327 of 10 December 1976 and the Order of 3 September 2010.

These texts define the technical characteristics that these instruments must have and the procedures for checking them. As with other categories of instruments, type examination and initial verification are mandatory before they are put into service.

Heat meters are also subject to periodic inspection, the frequency of which may vary depending on the technical characteristics of the instrument.

A special case concerns heating cost allocators, governed by decree no. 79-1232 of 31 December 1979 and several implementing orders. Although these devices are not, strictly speaking, meters, they are subject to specific rules because they are used to distribute charges in apartment blocks.

The compliance of these instruments with legal requirements is particularly important in the current context of controlling energy consumption and ecological transition, as underlined by our overview of legal metrology law.

Instruments in the fields of health and the environment

Ethylometers and fever thermometers

Measuring instruments used in the healthcare sector are subject to particularly stringent requirements, because of the potential implications for people's safety.

Breathalysers used to measure the concentration of alcohol in exhaled air are governed by decree no. 85-1519 of 31 December 1985 and the amended order of 8 July 2003. These instruments must pass a rigorous type examination and are subject to initial verification by a designated body. In service, they are subject to annual periodic inspection, given their importance in detecting road traffic offences.

With regard to fever thermometers, the Order of 7 July 1995 lays down the conditions for their construction and verification. It should be noted that since the decree of 24 December 1998, mercury fever thermometers designed to measure the internal temperature of humans have been banned from the market, for public health and environmental reasons.

For control thermometers used for perishable foodstuffs, the amended Order of 15 July 1997 lays down the applicable rules. These instruments play a crucial role in the cold chain and food safety.

Gas analysers and opacimeters

The instruments used for environmental measurements, particularly those used to monitor vehicle emissions, are subject to specific regulations.

Exhaust gas analysers are governed by the Order of 22 November 1996, amended by the Order of 7 March 2008. These instruments must conform to an approved type and undergo initial verification. In service, they are subject to annual periodic inspection by approved bodies.

For opacimeters, used to measure the opacity of smoke emitted by diesel engines, the decree of 22 November 1996, which has been amended several times, defines the conditions for their construction, inspection and use. As with gas analysers, periodic inspection is carried out annually.

These instruments play an essential role in vehicle roadworthiness testing and the fight against air pollution. Their accuracy is therefore a question of both regulatory compliance and public health.

Other environmental instruments are also regulated, such as sound level meters (amended decree of 27 October 1989) used to measure noise levels, particularly as part of the fight against noise pollution.

Legal consequences by category

Specific controls by category

The inspection procedures vary significantly depending on the category of instrument, reflecting their specific technical features and uses.

The frequency of in-service checks is an important aspect of this differentiation. It can range from one year for the most critical instruments (commercial scales, gas analysers) to several years for other categories.

The bodies authorised to carry out these checks may also differ depending on the category. For some very specific instruments, only bodies designated at national level are competent, while for others, bodies approved at departmental level may be involved.

The verification methods are adapted to the characteristics of each category. They may include tests for accuracy, reproducibility, stability over time, or resistance to certain environmental conditions (temperature, humidity, vibration, etc.).

This specific nature of the controls requires professionals to have precise knowledge of the obligations applicable to their instruments, knowledge that can be complex to acquire and keep up to date. experts in legal metrology law.

Specific penalties

While the general system of penalties set out in the Decree of 3 May 2001 applies to all categories of instrument, certain specific offences may be provided for in sector-specific legislation.

This is particularly the case for tachographs, the fraudulent handling of which is specifically punishable under article 19 of law no. 95-96 of 1 February 1995. Similarly, offences relating to instruments used to record road traffic offences (speedometers, breathalysers) may give rise to specific prosecutions, given their potential impact on legal proceedings.

In certain sectors, such as the agri-food or health industries, the consequences of non-compliance can go beyond the traditional administrative or criminal sanctions and lead to specific measures: withdrawal of products from the market, administrative closure of establishments, etc.

These particularities underline the importance for professionals to be familiar not only with the general framework of the control of measuring instrumentsThey must also be aware of the specific provisions applicable to their sector of activity and the instruments they use.

The diversity of regulated instruments and the complexity of the applicable texts often require in-depth legal expertise to navigate this technical area of the law, where obligations can vary considerably from one sector to another, and where a compliance error can have significant legal and economic consequences.

If you have any questions about the regulations specific to your sector of activity, please do not hesitate to contact our firm.