G-22—Measurement Canada policy for the type approval of telemetering devices used in gas trade measurement applications

Category: Gas
Issue date:
Effective date:
Revision number: 1
Supersedes: G-22


Table of contents


1.0 Purpose

The purpose of this bulletin is to clarify and summarize Measurement Canada's (MC) policy regarding the types of telemetering devices that are subject to approval specifications and requirements. For software controlled telemetering devices subject to approval, this bulletin identifies software functions that are deemed legally relevant and the provisions required to ensure their security.

2.0 Scope

This bulletin applies to telemetering functions and devices designed to be incorporated within, retrofitted to, or used as separate devices with meters approved by MC for use in gas trade measurement applications.

3.0 Definitions

Legally relevant (juridiquement pertinent)

Software, hardware, data or a part thereof which interferes with properties regulated by legal metrology.

Meter (compteur)

As defined in the Electricity and Gas Inspection Act, means an electric or gas meter and includes any apparatus used for the purpose of making measurements of, or obtaining the basis of a charge for, electricity or gas supplied to a purchaser.

Retrofit (rattrapage)

The addition of a component or an accessory to a meter that was approved and manufactured without the component or accessory.

Telemetering (télémesure)

The transmission of measurement information with the aid of intermediate means that permit the source electricity or gas meter's register reading to be duplicated and/or interpreted at a distance.

Note: In this definition, the term "intermediate means" is broad enough to include wire or wireless techniques for transmitting measurement data from the source electricity or gas meter.

Telemetering device (appareil de télémesure)

A device used in a telemetering system to duplicate the register reading of the source meter. The location of this device may be external or integral to the source meter with which it is used.

4.0 Approval specifications applicable to telemetering devices

Telemetering devices required to be approved by MC are subject, as applicable, to the following type approval specifications:

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

    The specifications apply to all telemetering functions and devices required to be approved by MC.

  2. S-EG-05—Specifications for the approval of software controlled electricity and gas metering devices.

    These specifications apply to all software controlled telemetering functions and devices required to be approved by MC.

  3. S-EG-06—Specifications relating to event loggers for electricity and gas metering devices.

    These specifications apply to all software controlled telemetering functions and devices required to be approved by MC where an event logger is intended to provide for software security.

  4. S-G-03—Specifications for the Approval of Type of Gas Meters, Ancillary Devices and Associated Measuring Instruments

    These specifications apply to all telemetering functions and devices required to be approved by MC. In particular, Part 12—Electrical Pulse Devices/Functions applies to all pulse based telemetering functions and devices including pulse generators and pulse receiving devices.

5.0 Telemetering device types not subject to approval by Measurement Canada

Telemetering devices designed as separate devices with the sole purpose of retransmitting unmodified, non-pulse-based legal units of measure (LUM) information received from the electronic register of an approved source meter or another telemetering device are not subject to approval by MC, provided they are not capable of inadmissibly interfering with the secured portion of the source meter.

6.0 Telemetering device's subject to approval by Measurement Canada

6.1 General

6.1.1 Telemetering devices deemed to fall within MC's legal definition of a meter are subject to type approval.

6.1.2 Telemetering functions or devices incorporated within a meter submitted for approval by MC are evaluated and approved as integral components of the meter and included in its Notice of Approval.

6.1.3 Retrofit-type and separate telemetering devices subject to approval by MC are evaluated and approved as separate devices and issued their own Notice of Approval.

6.2 Specific telemetering device types

The following specific types of telemetering devices are deemed to fall within the legal definition of a meter and are subject to approval by MC:

  1. Pulse generators designed to be incorporated within a meter or used as a separate device with a meter.
  2. Pulse receiving devices designed to be used as a separate device with one or more meters.
  3. Telemetering devices designed to be retrofitted to a source meter approved by MC. These retrofit-type telemetering devices tend to be software controlled, are driven by the source meter, generate pulses proportional to volume registered by the source meter, and count and record these pulses. They may transmit pulse totals and/or use pulse counts to calculate and then transmit volume LUM (e.g. duplicate the source meter's register reading) to a remote location. They may also include functions to modify calculated LUM and/or create new LUM information, either of which would then be transmitted to a remote location.

    The following are examples of pulse-based retrofit-type telemetering devices may be retrofitted to a source meter and driven by it to produce pulses proportional to registered volume:

    1. Telemetering devices designed to be installed between a source gas meter's mechanical output drive and its existing mechanical index. The meter drives the telemetering device which in turn drives the mechanical index. As the meter drives the telemetering device, its integral pulse encoder generates pulses proportional to the volume registered by the mechanical index.
    2. Telemetering devices with an integral mechanical index, designed to be installed on a source gas meter in place of its existing mechanical index. As the meter drives the telemetering device, its integral pulse encoder generates pulses proportional to volume registered by its integral mechanical index.
    3. Telemetering devices with a proximity sensor, designed to be installed under the cover of a source gas meter's mechanical index in the vicinity of a particular dial or odometer drum. The sensor detects movement of the dial or drum and produces one or more pulses for each revolution.
    4. Telemetering devices with a pulse encoder, designed to be installed under the cover of a source gas meter's mechanical index and physically driven by a particular dial. The pulse encoder produces one or more pulses for each revolution of the driving dial.
  4. Pulse-based telemetering devices designed to be incorporated within the mechanical index of a meter by the meter manufacturer. These may be similar in design and operation to a retrofit-type telemetering device described under 6.2(c).
  5. Non-pulse-based telemetering functions designed to be incorporated within a software-controlled meter by the meter manufacturer. The function accesses an electronic register(s) containing LUM information and transmits the contents unmodified to a remote location.
  6. Separate telemetering devices designed to receive non-pulse-based LUM information from the electronic register of a source meter and having the capability of modifying this LUM information and/or creating new LUM information, either of which would then be transmitted to a remote location.

7.0 Approval evaluation of retrofit-type telemetering devices for compatibility with the source meter(s)

Retrofit-type telemetering devices submitted for approval are evaluated to ensure they do not impair or impact the operation of the approved source meter makes/models intended to be retrofitted.

8.0 Approval evaluation of telemetering device software

In the case of software controlled telemetering devices submitted for approval, it is necessary to establish if their software is legally relevant, legally non-relevant, or a combination of both to assess the suitability and effectiveness of their provisions for sealing.

8.1 Legally relevant telemetering device software

8.1.1 Whether separate, retrofit-type, or incorporated within a meter, a telemetering device's software is deemed legally relevant if it performs any of the following functions:

  1. Recording and totalizing pulses from a pulse generator.
  2. Calculation of a LUM by the application of a fixed or user-configurable scalar factor or multiplier to pulses received by or generated within the telemetering device. For example:
    1. calculated mass LUM = # pulses × (mass LUM / pulse)
    2. calculated volume LUM = # pulses × (volume LUM / pulse)
  3. Modification of received or calculated LUM by the application of fixed or user-configurable scalar factor(s) or multiplier(s). For example:
    1. modified volume LUM = received or calculated volume LUM × pressure multiplier
    2. modified volume LUM = received or calculated volume LUM × pressure multiplier × supercompressiblity factor (Fpv2)
    3. modified volume LUM = received or calculated volume LUM × metric conversion factor
  4. Calculation of new LUM from received, calculated or modified LUM by the application of fixed or user-configurable scalar factor(s) or multiplier(s). For example:
    1. new volume LUM = received or calculated mass LUM / mass density
    2. new energy LUM = (received or calculated mass LUM / mass density) × heating value
    3. new energy LUM = received or calculated volume LUM × heating value
    4. new volume or energy LUM = new volume or energy LUM × metric conversion factor

8.2 Legally non-relevant telemetering device software

8.2.1 Whether separate, retrofit-type, or incorporated within a meter, a telemetering device's software may be deemed legally non-relevant if it does not interfere with properties regulated by legal metrology and it is distinctly separated from and cannot inadmissibly influence legally relevant software.

8.2.2 Examples of telemetering software that may be deemed legally non-relevant (subject to evaluation against and compliance with S-EG-05) include:

  1. Telecommunications software incorporated within a software-controlled gas meter that is separated from its legally relevant software and is designed for the sole purpose of interfacing with the legally relevant software to read and transmit unmodified LUM to a remote location.
  2. Telecommunications software within a retrofit-type or separate software controlled telemetering device that is separated from its legally relevant software and is designed for the sole purpose of interfacing with that legally relevant software to read and transmit to a remote location any of the following:
    1. pulse count totals
    2. calculated LUM representing a duplication of the source meter's register reading
    3. modified LUM
    4. new LUM

9.0 Provisions for sealing and securing

Approval specifications referenced in section 4.0 include requirements for devices to be designed with provisions for sealing and securing their legally relevant hardware, software, data or any part thereof. These requirements are applicable to all telemetering devices subject to approval by MC.

10.0 Revisions

The purpose of revision 1 was to:

Date modified: