GEN-49—Temporary procedures for selecting random samples of meters for compliance sampling

Category: General
Issue date: 2022-12-16
Effective date: 2022-12-16
Revision number: 1
Supersedes: GEN-49

Table of contents

1.0 Purpose

This bulletin contains a modified policy and procedures for selecting random samples of meters from a given lot of homogeneous meters for compliance sampling pursuant to the requirements of specification S-S-06—Sampling Plans for the Inspection of Isolated Lots of Meters in Service.

Note: This bulletin was issued in 2020 due to the difficulties encountered by contractors (meter owners) in accessing meters as a result of the restrictions imposed to contain the COVID‑19 pandemic.

2.0 Authority

This bulletin is published pursuant to section 19 of the Electricity and Gas Inspection Regulations.

3.0 Scope

This bulletin applies to the selection of random samples of meters to determine the compliance of lots of electricity and gas meters where a temporary dispensation has been granted to an electricity or gas contractor (meter owner) in accordance with a risk management framework (RMF).

Note: Where a temporary dispensation has not been granted, the procedures for selecting sample meters are those set out in S-S-06. All meters in the lot without exception are subject to random sampling without the replacement options outlined in this bulletin.

4.0 Context

In the context of the COVID-19 pandemic, several measures were put in place to ensure the health and safety of Canadians. These measures were administered by public health authorities in each province and territory. Due to these measures, it was difficult or impossible to access or retrieve meters for testing.

In response, Measurement Canada created temporary procedures for sample meters to be selected at random, from a list of meters in the lot presumed to be accessible while the pandemic restrictions were in effect. Meters that were not accessible by the owner, retained their status as part of the lot.

The residual effects of the COVID-19 pandemic continue to put a burden on the supply chain. Measurement Canada also acknowledges that future supply disruptions are conceivable. For this reason, the procedures outlined in this bulletin will remain in effect in the event of future unforeseen and extraordinary circumstances and will be guided by the eligibility criteria of an RMF.

5.0 References

Electricity and Gas Inspection Regulations

S-E-02—Specifications for the Verification and the Reverification of Electricity Meters

S-G-02—Specifications for the Verification and Reverification of Diaphragm Meters

S-S-01—Specifications for Random Sampling and Randomization

S-S-06—Sampling Plans for the Inspection of Isolated Lots of Meters in Service

6.0 Meter sample selection procedures

6.1 Sample selection where the inspection has not yet started

  1. Before starting the sample selection process, form a lot of meters that are homogeneous with respect to the requirements in Annex A of specification S-S-06.
  2. From the main list of meters in the lot, apply a filter to identify all meters presumed to be available, taking into account any impediment caused by the circumstances the meter owner is facing. A new list of available meters in the lot is then generated. These meters are subject to random sampling based on the entire lot population in accordance with the requirements of section 5.2 and appendices B and C of specification S-S-06.
  3. If the minimum sample size (nmin) value cannot be reached due to the unexpected unavailability of meters discovered during the sampling process, generate additional meter samples from a new filtered list of available meters. Repeat this step until the nmin value is reached.
  4. List the meters that aren't available because of impediments and provide the reasons why they aren't available. Here are some examples of reasons why meters aren't available:
    • Customer refuses access to an indoor installation,
    • Restricted regional mobility,
    • Site access requires travelling under unsafe sanitary conditions,
    • Site can't be accessed due to public health restrictions (e.g. lockdown, quarantine)
    • Replacement meters or meter parts are not available due to supply constraints.

6.2 Sample selection where the inspection started before the publication of this bulletin and for which the nmin could not be reached

  1. Replace sample meters that became unavailable with additional sample meters from a complementary list, as applicable.
  2. Select these additional sample meters at random from a filtered list of meters in the lot that are presumed to be available while impediments remain.
  3. Repeat step 2 until the nmin value is reached. The complementary list's sample size may be larger than the number of meters required to reach the nmin value.

Example: In a lot of 3,000 meters, the required nmin value is 125 sample meters; however, because of meter inaccessibility related to access restrictions, only 100 meters could be retrieved. A complementary filtered list of at least 25 accessible meters may then be generated to continue the retrieval of sample meters following the order of selection from this list until an additional 25 meters are retrieved and the nmin value is reached.

7.0 Meter sampling records

The meter owner must retain all meter sampling records and associated lists that were used to process the lot's compliance pursuant to this bulletin. These records must be made available to MC for audit purposes upon request.

8.0 Revisions

The purpose of this revision was to expand the scope of this bulletin beyond the COVID-19 pandemic in order to include temporary measures for future unforeseen or extraordinary circumstances deemed eligible by MC.

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