S-EG-02—Specifications for approval of physical sealing provisions for electricity and gas meters

Category: Electricity and gas
Specification: S-EG-02 (rev. 3)
Issue date:
Effective date:
Supersedes: S-EG-02 (rev. 2)


Tables of contents


1.0 Purpose

The purpose of these specifications is to amend Measurement Canada's (MC) specifications LMB-EG-07 and S-G-03 to include requirements pertaining to provisions for the physical sealing of electricity and gas meters.

2.0 Scope

These specifications apply to all electricity and gas meters which are intended to be used in revenue metering.

3.0 Authority

These specifications are issued under the authority of section 12 of the Electricity and Gas Inspection Regulations.

4.0 References

5.0 Definitions

Authorized service provider (fournisseur de services autorisé)

An organization that has been accredited for the verification and/or reverification of meters under the Electricity and Gas Inspection Act (an accredited meter verifier).

Conventional seal (sceau classique)

A metallic double sleeve crimp-type seal.

Conventional sealing method (méthode de scellage classique)

The wire-based method used to secure a meter by using a metallic multi-strand or braided wire having a diameter of at least 0.644 mm in conjunction with a conventional seal.

Legally relevant parameter (paramètre juridiquement pertinent)

A parameter of a measuring instrument, electronic device or a sub-assembly subject to legal control. Legally relevant parameters typically form part of the legally relevant functions performed by a device. The following types of legally relevant parameters can be distinguished: type-specific parameters and device-specific parameters. For the purposes of these specifications, legally relevant parameters are those parameters which are, either individually or as part of a function, subject to verification under the Electricity and Gas Inspection Act.

Meter terminal (borne de compteur)

A wiring connection on an electricity or gas meter which allows for electrical input power and/or measurement inputs and outputs.

Seal (sceau)

A physical mechanism that is used to secure access to a meter's metrological adjustments and legally relevant parameters so that access or changes to metrological adjustments and legally relevant parameters will be detectable.

Sealing (scellage)

An action performed in order to secure a device. Securing a device includes, but is not limited to, sealing a cover to the base of an electricity meter, sealing an enclosure containing a multiple customer metering system, sealing adjustment chamber ports on a gas meter and sealing one meter module to another meter module (such as a temperature compensating module to a rotary meter.

Verification mark (marque de verification)

A mark applied at the time of verification to a device that has been found to be in compliance with the Electricity and Gas Inspection Act. A verification mark includes any seal, stamp, tag or label which identifies the verifier and the year in which the verification takes place.

6.0 General

The intent of the approval requirements pertaining to meter construction (established in LMB-EG-07 and S-G-03) is to ensure that approved and verified meters are capable of being sealed in a manner which conforms to MC's sealing principles and policies. The requirements contained in these specifications supplement the requirements established in LMB-EG-07 and S-G-03, and have been established in accordance with MC's Principles for Sealing Meters and Trade Devices (refer to the Appendix). These requirements for physical sealing provisions align with international requirements for physical sealing provisions established by the Organisation Internationale de Métrologie Légale (OIML).

7.0 Meter type approval requirements – physical sealing provisions

This section describes the specific requirements that apply to the type approval of meters and the means provided for the physical sealing of meters used for trade measurement.

7.1 Meter case

In support of MC specification LMB-EG-07 for electricity meters and S-G-03 for gas meters, unless otherwise permitted by the President of MC pursuant to the Electricity and Gas Inspection Regulations, the following requirements shall apply.

7.1.1 Subject to section 7.1.4 below, a meter shall have a case which can be physically sealed using the conventional sealing method defined in the Definitions section.

7.1.2 Where a meter sealed using the conventional sealing method contains more than one seal point on the meter, the manufacturer shall identify the applicable sealing configuration(s) required to secure the meter.

7.1.3 Once a meter is sealed, any access that may permit tampering for the purpose of deliberate manipulation of internal parts or metrological functions of the meter shall cause permanent visible evidence of such tampering or attempted tampering. Evidence of tampering includes, but is not limited to, damages such as breakage, cracks and scratches to the meter case, cover, enclosure, internal parts and components, or the meter seal.

7.1.4 Meters may be constructed in a manner which does not comply with the requirements of 7.1.1 only where the design of the meter is such that it would not be possible to gain access to the meter's metrological adjustments or working parts without permanently damaging the meter cover or case.

7.1.5 For the purpose of meter type approval, the meter's physical sealing provisions shall be evaluated principally, but not exclusively, by means of a visual examination. MC may perform a physical test to determine compliance with the requirements of section 7 of these specifications. In any case where it is determined, at the time of or following the granting of type approval, that the meter's physical sealing provisions may be subverted in a manner which leaves no discernible evidence of tampering, the meter manufacturer shall be responsible for any and all corrective actions required to ensure that the approved pattern complies with section 7.1.3.

7.1.6 The meter's physical sealing provisions and applicable sealing configuration(s) shall form part of the meter's approved pattern which will be documented in the Notice of Approval issued by MC for the meter. It should be noted that information contained in the Notice of Approval regarding the meter's physical sealing provisions does not prescribe the type of seal that may be applied during verification.

7.2 Meter terminals

7.2.1 Electricity meters

In support of the terminal sealing requirements prescribed in LMB-EG-07, the following requirements shall apply.

7.2.1.1 With the exception of S-base meters and back-connected switchboard meters, a meter shall provide physical means to seal meter terminals using the conventional sealing method.

7.2.1.2 Once the meter terminals are sealed using the conventional sealing method, any access to the meter terminals shall cause permanent visible damage to the case or the seal used for the purpose of testing (i.e. disassembly of the case must either break or crack the casing material or break the seal wire).

7.2.1.3 The physical sealing provisions for meter terminals shall comply with the requirements of clauses 7.1.2, 7.1.5 and 7.1.6.

7.2.2 Gas meters

In addition to the sealing requirements of S-G-03, the following requirements shall apply.

7.2.2.1 A meter shall provide physical means to seal the terminals using the conventional sealing method.

7.2.2.2 Once the meter terminals are sealed using the conventional sealing method, any access to the meter terminals shall cause permanent visible damage to the case or the seal used for the purpose of testing (i.e. disassembly of the case must either break or crack the casing material or break the seal wire).

7.2.2.3 The physical sealing provisions for meter terminals shall comply with the requirements of clauses 7.1.2, 7.1.5 and 7.1.6.

7.3 Communication ports

Electronic meters equipped with a communication port (such as an optical port or RS-232 connection) shall be equipped with physical sealing provisions placed either on the communications port or on a sealable plate which covers a read-write switch, jumper or other suitable means which provide an equivalent level of protection. Physical sealing of the meter's communication port using the conventional sealing method shall facilitate the prevention or detection of unauthorized changes made via the communication port to any legally relevant parameters, metrological configuration settings, and/or cumulative meter readings (e.g. energy, volume or mass).

7.4 Batteries (gas meters only)

In addition to the sealing requirements of S-G-03, for electronic gas metering devices which employ one or more batteries as the main power source and/or as a back-up power source, sealing provisions designed to accommodate a conventional or alternative sealing method shall be provided to prevent unauthorized access to the battery or battery compartment.

8.0 Revisions

8.1 The purpose of revision 3 was to:

8.2 The purpose of revision 2 was to:

8.3 The purpose of revision 1 was to clarify the existing policy concerning deliberate manipulation, tampering and manufacturer's responsibility for corrective actions required to ensure that the approved pattern complies with the requirements if a nonconformity is found. Only sections 7.1.3 and 7.1.5 were changed.

Appendix – Principles for sealing meters and trade devices

MC has established the following general principles for sealing meters and other trade measurement devices. These principles have been established to protect all parties to a trade measurement transaction equally and without bias.

  1. The functions of a seal are to:
    1. secure a device so that access or changes to metrological adjustments, legally relevant software and parameters will be detectable;
    2. identify the verification date and organization which verified the device. This information is necessary for the administration and enforcement of legislation, for complaint or dispute investigation purposes, for the determination of the seal expiration date and for compliance sampling (seal extension) purposes; and
    3. act as a deterrent against unauthorized access or changing of metrologically sensitive adjustments and legally relevant parameters.
  2. A seal is required whenever a meter (defined pursuant to the Electricity and Gas Inspection Act is verified for trade use and it is possible to affect the metrological adjustments or legally relevant parameters of the device.
  3. A seal or verification mark can only be applied by an authorized service provider or an inspector designated under the Electricity and Gas Inspection Act.
  4. A seal is a vital component of a credible measurement system which provides confidence in the integrity and accuracy of measurement in the following manner:
    1. An intact seal provides evidence of and confidence in the integrity of the meter and the measurement information it contains. This evidence is independent of either of the parties (purchaser or seller) which have a stake in the veracity of the measurement information, which is especially important in the case of a measurement dispute investigation.
    2. An intact seal provides a level of assurance that the device complies with metrological criteria established by an independent party (MC) under the general direction of federal legislation.
    3. The markings on a seal are used to determine when and by whom the meter was verified, which is one of the key factors in ascertaining whether or not the sealed meter conforms to legislated requirements.
    4. Seals are an important part of the process of determining the validity of sample meters inspected pursuant to seal date extension programs.
  5. A verification mark does not constitute a seal pursuant to the Electricity and Gas Inspection Act, but may be included on a tag used for sealing. A verification mark is a mark which is applied, at the time of verification, to a device that has been found to be in compliance with the applicable legislation (i.e. typically on a seal tag or an adhesive sticker). Its primary purpose is to indicate to the public that the device has been officially examined and verified by an MC inspector or an authorized service provider. The use of a verification mark also indicates an MC presence in the marketplace, providing confidence in a device's accuracy and integrity. Finally, a verification mark provides a link to the organization which verified the device. This information is valuable in tracing records relating to the verification of the device.
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