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A-2 — Calibrations of standards and measuring apparatus owned and used by authorized service providers to conduct inspections

Category: Programs for authorized service providers
Issue date:
Effective date:
Revision number: 12
Supersedes: A-2 (rev. 11)


Table of content


1.0 Purpose

The purpose of this bulletin is to outline how Measurement Canada (MC) determines the number of standards and measuring apparatus owned by authorized service providers (ASPs) that are calibrated by MC for use by ASPs to conduct inspections (examinations). It also sets out ASPs' responsibilities in this regard and the conditions under which weights and measures calibrations are provided by MC free of charge.

2.0 Scope

This bulletin applies to standards and measuring apparatus owned and used by ASPs to conduct inspections (examinations) pursuant to the Electricity and Gas Inspection Act and the Weights and Measures Act. Information on the calibration of other standards can be found in bulletin GEN-08. Bulletin GEN-08 cannot be used to circumvent the requirements of the present bulletin.

3.0 Definitions

Note: For the purposes of this bulletin, the term "inspection" is used in a generic manner and is intended to include verifications and reverifications under the Electricity and Gas Inspection Act and examinations under the Weights and Measures Act.

Calibration

(étalonnage)

A comparison between a standard under test and a reference standard for the purpose of determining if the value of the standard under test is within the specified tolerances.

Note: The term "calibration" does not necessarily include the adjustment of a standard required to ensure it meets specified tolerances.

Measuring apparatus

(appareil de mesure)

An apparatus required for the measurement of electricity or gas or the inspection of meters.

Standard

(étalon)

Any standard designated as a local standard by the Minister under section 13 of the Weights and Measures Act.

4.0 Responsibilities of authorized service providers

Authorized service providers are responsible for the following:

  1. Ensuring their standards and measuring apparatus are calibrated and certified at least at intervals prescribed by the Weights and Measures Regulations or the Electricity and Gas Inspection Regulations.
  2. Ensuring standards and measuring apparatus submitted for certification by MC are in good condition and properly cleaned and marked.
  3. Ensuring mass standards are adjusted as outlined in this bulletin or in the Laboratory Manual for the Evaluation of Weight Kits before submitting them for certification by MC.
  4. Ensuring, for companies seeking accreditation or registration, standards and measuring apparatus are submitted for calibration only when instructed by the Regional Manager, Alternative Service Delivery (ASD) or the Regional Coordinator, ASD, or his or her delegate.
    1. Under the Accreditation Program, standards and measuring apparatus must be submitted for calibration when the quality management system documentation review is completed (or very close to completed) by MC.
    2. Under the Registration Program, standards must be sent for calibration when at least one technician has successfully passed the theoretical training and the associated practical evaluation is very close to being completed.
  5. Contacting MC's Approval and Calibration Services Laboratory (ACSL) or district office, as appropriate, to make prior arrangements before sending standards and measuring apparatus for calibration and certification.
  6. Ensuring that the number of standards and measuring apparatus submitted for certification by MC is:
    1. commensurate with the number of recognized technicians and the expected inspection workload to be performed, and
    2. necessary to fulfill mandatory inspection requirements.
  7. Ensuring all standards and measuring apparatus sent to MC's ACSL are accompanied by a correctly completed Calibration Services Request form.
    1. A written explanation as to why a standard or measuring apparatus has been sent for recalibration with an expired certification, a broken seal or in a condition affecting the certificate's validity, must accompany the form.
    2. The address to which the standard or measuring apparatus is to be returned and, if different, the address to which the certificate of designation is to be sent must be indicated on the form.
  8. Ensuring all standards and measuring apparatus sent to MC's ACSL are properly packaged to ensure adequate protection during shipping.
  9. Sending standards and measuring apparatus to MC upon request prior to the end of the prescribed certification interval for the purpose of verifying their condition, establishing their "as found" value, and determining whether an ASP is maintaining its standards and measuring apparatus in satisfactory condition.
  10. Assuming all packaging, shipping and handling costs and any brokerage fees for international shipments associated with the certification of the standards and measuring apparatus.

ASPs must submit the complete list of all the standards and measuring apparatus they would like MC to certify and designate to the Regional Coordinator, ASD for acceptance. The list must be kept up to date by the ASPs and all changes must be approved by the Regional Coordinator, ASD. The standards and measuring apparatus not approved on the list will not be calibrated by Measurement Canada.

Weights and measures standards used to perform inspections are calibrated and certified as local standards by MC free of charge, in accordance with section 59 of the Weights and Measures Regulations. See Appendix A for the maximum number of weights and measures standards that can be calibrated and designated as local standards by MC free of charge.

Measuring apparatus used to conduct inspections pursuant to the Electricity and Gas Inspection Act are calibrated and certified in accordance with section 47 of the Electricity and Gas Inspection Regulations. At this time, there is no maximum number of measuring apparatus that can be accepted by the Regional Coordinator, ASD. Fees apply to the calibration of electricity and gas measuring apparatus.

5.0 Accuracy requirements

Standards presented for calibration and certification must meet the accuracy requirements set out in Schedule IV of the Weights and Measures Regulations.

Measuring apparatus presented for calibration and certification must meet the accuracy requirements set out in the Electricity and Gas Inspection Act and Regulations.

6.0 Types of standards and measuring apparatus and their calibration location

Table 1: Standards and measuring apparatus and calibration locations
Standard type Calibration location
Dimensional
Gauge block CLAS laboratory or laboratory recognized by the NRC providing traceability to the definition of the metre as per the Weights and Measures Act.
Tape measure CLAS laboratory or laboratory recognized by the NRC providing traceability to the definition of the metre as per the Weights and Measures Act.
Electrical
Digital multifunction standard MC's ACSL, Standards Building (Ottawa)
Gas
Barometer On-site calibration by MC's ACSL
Bell prover MC's ACSL, Standards Building (Ottawa)
Dead weight tester, pneumatic MC's ACSL, Standards Building (Ottawa)
Pressure gauge MC's ACSL, Standards Building (Ottawa)
Pressure module MC's ACSL, Standards Building (Ottawa)
Pressure transducer MC's ACSL, Standards Building (Ottawa)
Pressure controller MC's ACSL Standards Building (Ottawa)
Gravimetric
Mass standards of 5 kg or larger (7.1.1) MC district offices or CLAS Type I laboratories recognized by MC
Mass standards of 5 kg or smaller (7.1.2) MC ACSL Standards Building (Ottawa) or CLAS Type I laboratories recognized by MC
Mass standards of 20 kg or smaller (7.1.3) MC's ACSL, Standards Building (Ottawa)
Temperature
Thermometer (7.3) MC's ACSL, Standards Building (Ottawa)
Volumetric
Narrow neck 20 L standard (7.2) MC's ACSL, Standards Building (Ottawa)
Test measure and prover of 100 L and less used to calibrate other provers (7.2) MC's ACSL, Standards Building (Ottawa)
Test measure and prover used to inspect volumetric meters (7.2) MC district offices
Pipe prover (7.2) MC district offices
Hydrometer/LPG MC's ACSL, Standards Building (Ottawa) or
National Research Council of Canada (NRC), Ottawa
Pycnometer MC's ACSL, Standards Building (Ottawa)

7.0 Information on standard types

7.1 Gravimetric standards

Mass standards that are used to inspect Class III, III HD and IIII weighing devices must meet the tolerances prescribed in parts III or IV of Schedule IV of the Weights and Measures Regulations. These tolerances are roughly equivalent to International Organization of Legal Metrology (OIML) Class M1 tolerances.

Mass standards that are used to inspect Class II weighing devices must meet the tolerances prescribed in Part I of Schedule IV of the Weights and Measures Regulations. These tolerances are roughly equivalent to OIML Class F2 tolerances.

Weight kits that are calibrated by the ACSL must meet one half of the prescribed tolerances in order to be certified. The purpose of this provision is to ensure that, during the certification period, the error of mass standards does not exceed the tolerance prescribed in the Weights and Measures Regulations.

Please consult your regional auditor as your first point of contact at Measurement Canada for advice on the selection of mass standards 5 kg and greater or the ACSL for all other weight kits.

7.1.1 OIML Class M1 mass standards of 5 kg or larger

Mass standards (usually cast iron or fabricated weights) of 5 kg or larger (10 lb or larger) must meet all requirements, including those relating to construction, material and fabrication defined in OIML R111-1 and Appendix B of this document. It is recommended that organizations consult their local regional auditor as the first point of contact at Measurement Canada prior to the purchase or fabrication of any new weight design.

Before being submitted for calibration and certification, mass standards must be cleaned and prepared in accordance with the procedure described in Appendix B of this document. Mass standards which deviate from the nominal value (error) by more than two thirds of the prescribed tolerance will have to be adjusted as close as possible to the nominal value. ASPs must provide the necessary personnel to assist in making these adjustments. The purpose of adjusting mass standards as close as possible to the nominal value is to ensure that, during the certification period, the error of mass standards does not exceed the tolerances prescribed in the Weights and Measures Regulations.

7.1.2 OIML Class M1 mass standards of 5 kg or smaller

These standards are also known as "inspector weight kits". They consist of weights of 5 kg (10 lb) to 10 mg (0.001 lb or 1/32 oz) and are mainly used to inspect Class III, IIIHD and IIII devices.

These weight kits must meet all of the requirements found in the Laboratory Manual for the Evaluation of Weight Kits. Weight kits that do not meet these requirements, including those that are not properly cleaned, marked or adjusted as required will be returned to their owner without being certified. The ACSL does not provide weight cleaning, stamping or adjustment services. More information can be found in the above-mentioned laboratory manual.

Note: NIST (National Institute of Standards and Technology) Class F has larger tolerances than those prescribed by the Weights and Measures Regulations. Weights calibrated to the NIST Class F tolerances will typically have to be adjusted before being sent to MC.

7.1.3 OIML Class F2 or better mass standards of 20 kg and smaller used to inspect Class II devices (high precision weight kits)

These standards are also known as "precious metal weight kits". They consist of weights of 20 kg to 1 mg and are used to inspect Class II devices. They should only be used for the inspection of legal for trade Class II devices. The standards in those weight kits must be used with caution; otherwise, the integrity of the weights may be compromised and they may be outside the prescribed tolerance before the end of their calibration cycle.

These weight kits must meet all of the requirements found in the Laboratory manual for the evaluation of weight kits. Weight kits that do not meet these requirements, including those that are not properly cleaned, marked or adjusted as required will be returned to their owner without being certified. MC's ACSL does not provide weight cleaning, stamping or adjustment services. More information can be found in the Laboratory manual for the evaluation of weight kits.

7.1.4 Program for the recognition of calibration results from CLAS laboratories

High precision weight kits (section 7.1.3) are not presently considered under the program for the recognition of calibration results from CLAS laboratories. All high precision weight kits used for the inspection of legal for trade Class II devices must be sent to MC for calibration and certification.

Mass standards that are suitable for the inspection of Class III, III HD and IIII weighing devices (section 7.1.2) must be submitted to MC for initial evaluation. Only subsequent evaluations can be performed by a recognized CLAS Type I laboratory under the above-mentioned recognition program.

ASPs using the services of a laboratory recognized under the program for the recognition of calibration results from CLAS laboratories for the calibration of their weights and weight sets must meet the requirements specified in 4.0 a, f and i. The requirements specified in 4.0 f are applicable to weights and weight kits certified and designated as standards and not to other weights and weight kits ASPs may need to have calibrated. The requirements of sections 7.1.1 and 7.1.2 must also be met. Mass standards can be cleaned, stamped and adjusted by a CLAS Type I Laboratory.

All weights and weight kits sent to a CLAS Type I laboratory must be properly packaged to ensure adequate protection during shipping. They must also be accompanied by a correctly completed Calibration Services Request form and the last calibration certificate issued by MC.

7.2 Volumetric standards

Volumetric standards must meet all requirements, including those relating to construction set out in MC's Guidelines for the Calibration and Certification of Volumetric Standards, available from your MC contact. It is recommended that organizations consult the MC Regional Volumetric Specialist prior to the purchase or fabrication of any new standards design and equipment not included in MC's guidelines.

Before being submitted for calibration and certification, volumetric standards must be cleaned. Walls must be free of greasy or oily residue, dirt and rust. The coating on the inside surface of standards must be in good condition with no obvious peeling. The standards must be free of flammable or noxious vapours.

The ACSL and MC district offices do not clean volumetric standards. Volumetric standards that do not meet construction requirements or are not properly cleaned will be returned to their owner without being certified.

7.3 Temperature standards

Temperature standards must meet the accuracy requirements set out in Schedule IV to the Weights and Measures Regulations. It is recommended that organizations consult the local MC regional volumetric or gas specialist prior to the purchase of temperature standards.

For the specified application, thermometers must meet the minimum temperature range and resolution indicated below.

Table 2: Minimum ranges and resolutions for thermometers
Application Minimum temperature range Minimum resolution
General field inspection −30 °C to +50 °C 0.1 °C
Calibration of thermometers used in gas prover for temperature correction 0 °C to +35 °C 0.01 °C
Temperature correction in gas measuring apparatus 0 °C to +35 °C 0.1 °C
Bell prover air temperature 0 °C to +35 °C 0.1 °C

Thermometers intended for field use must be stored in a hard protective carrying case with foam inserts cut to the shape of the thermometer and the probes or similar means to protect them. The carrying case must have sufficient padding to prevent breakage of the thermometer and the probes.

The following information must be permanently marked, or be capable of being displayed on thermometers: manufacturer's name, model number and serial number. In the case of thermometers with multiple probes, each probe must be marked by a unique identifier.

Where the instrument is capable of being calibrated or adjusted, access to the adjustments must be easily detectable or sealable.

8.0 Revisions

The purpose of revision 12 was to:

The purpose of revision 11 was to:

The purpose of revision 10 was to:

The purpose of revision 9 was to:

The purpose of revision 8 was to clarify:

The purpose of revision 7 was to:

The purpose of revision 6 was to:

The purpose of revision 5 was to:

The purpose of revision 4 was to:

The purpose of revision 3 was to:

The purpose of revision 2 was to clarify:

The purpose of revision 1 was to:

9.0 Additional information

For additional information regarding this bulletin, please consult the contact us section of the Measurement Canada website or your departmental contact. The copy of this document located on Measurement Canada's website is considered to be the controlled copy.

Appendix A — Number of standards certified and designated as local standards by Measurement Canada free of charge for weights and measures authorized service providers

The maximum number of standards MC can certify and designate as local standards free of charge for weights and measures authorized service providers (ASPs) is set out below.

When the number of standards to be submitted by an ASP exceeds the limits listed below, the ASP must provide a written justification to the local Regional Coordinator, ASD explaining the reason why the additional standards require MC certification and designation.

MC can also designate any supplementary standards calibrated by a recognized laboratory under the program for the recognition of calibration results from CLAS laboratories as long as they are used to inspect devices.

A1.0 Gravimetric standards

Mass standards of 5 kg or larger:

Large test weights (gravimetric standards in excess of 100 kg):

Mass standards of 5 kg and smaller (inspector's weight kit):

Note: The definition and contents of a weight kit are defined in the Laboratory manual for the evaluation of weight kits.

Mass standards of 20 kg and smaller used to inspect Class II devices (weight kits):

Note: The definition and contents of a weight kit are defined in the Laboratory Manual for the Evaluation of Weight Kits.

A2.0 Temperature standards

Thermometer:

A3.0 Volumetric standards

Volumetric prover standards (20 L measures) used to inspect volumetric meters like dispensers:

Volumetric prover standard used to inspect volumetric meters (gravimetric prover, open neck prover, pipe prover, pipe prover with entirely mechanical means of registration and vapour displacement prover):

Hydrometer / liquefied petroleum gas (LPG) dispenser:

Reference meter prover associated with the volumetric prover standard (20 L measures) to satisfy legal requirements of the certificate of calibration:

Test measure and prover of 100 L and less used to calibrate other provers or used to certify ASPs' pipe provers:

Pycnometer:

Pressure gauge:

Appendix B — Calibration procedures for standards of mass

The information that follows is an excerpt from RP-01 Field: Calibration Procedures for Standards of Mass (sections 2.4 to 2.72). The section numbering has been modified for use in this document.

B1.0 Material and fabrication requirements for mass standards

For specifications regarding material, construction, shape, density, surface conditions, etc. of mass standards, the international recommendation OIML R111-1: Weights of classes E1, E2, F1, F2, M1, M1‑2, M2, M2‑3 and M3 should be consulted. Questions regarding design or acceptability of standards and industry weights should be addressed to your regional auditor as your first point of contact. Requirements for these types of weights can be found in the Laboratory manual for the evaluation of weight kits.

To ensure consistency with past practice, the following should be observed in addition to the requirements of OIML R111-1 for standards equal to or larger than 10 kg.

B1.1 Design

Standards of a nominal value equal to or greater than 10 kg must be either "solid", "layered" or "filled" as defined below:

Note: The use of industry weight baskets or weight racks is prohibited.

B1.2 Seams

All exposed seams must be joined with a continuous weld to form a closed system (with the exception of the seal and plug). Where seams may come in contact with other objects during normal use, the weld on these seams must be ground smooth and flush with the surrounding metal.

All welds must be sufficiently strong to withstand, without breaking or cracking, all forces encountered during normal use.

B1.3 Shape

The shape of the standard must be simple without undue sharp angles and any exterior corners must be rounded to a radius no smaller than 6 mm.

B1.4 Surface roughness

The entire surface must be smooth and reasonably free from grooves and/or indentations in which foreign matter may accumulate.

B1.5 Density

The density of any material used to construct standards must be such that when the actual air density at calibration is ± 10% away from the conventional value of 1.2 kg/m3, the total density of the standard does not cause a change in the calculated value of the conventional mass exceeding 1/3 of the tolerance for the standard being calibrated or certified.

Although Table 5 of OIML recommendation R111 (2004) states the minimum and maximum densities of various classes, all standards equal to or larger than 10 kg used by MC should have the following minimum and maximum densities:

MC imposes more stringent requirements for density because otherwise the effect of the variations in air density and of the uncertainty due to the material density of the standard would make its combined uncertainty too large.

Note that grey cast iron has an approximate density of 7 000 kg/m3 and the lowest density for cast iron is 6 000 kg/m3.

B1.6 Material hardness

The material used must not be softer than brass and must be of suitable hardness and ductility to resist stress, wear and chipping to which standards may be subjected under normal use.

B1.7 Adjustment cavities

Standards must have one but no more than two adjustment cavities. The total volume of the cavity must be as close to, but must not exceed, 5% of the total volume of a standard.

Cavity enclosure must result in a closed system with provisions made for the imprint of an inspection mark. To ensure that no liquids can enter and accumulate in cavities, adequate means for sealing must be provided with an undercut opening or other to ensure that lead is securely held in place to seal the opening. No lead must project beyond the surface of the standard.

B1.8 Flaws

A cast iron standard must be examined to ensure there are no cracks or flaws and the adjustment cavities are free of foreign matter.

The Rz (maximum height of roughness profile) of the surface finish of any new cast iron standard must not exceed 12.5 μm (500 μin). The Ra (mean height of roughness profile) of the surface finish must not exceed 2.5 μm. A further examination must be made to ensure that the standard does not contain casting defects. Any depression deeper than 2 mm from the surrounding surface and at any point wider than 4 mm must be filled by welding to prevent accumulation of added weight after calibration. The use of foundry putty or body filler is not acceptable.

B1.9 Nominal values

Standards should be constructed to represent nominal values of mass of denominations of 1, 2 and 5 x 10n, where "n" is a positive or negative whole number or zero. Nominal values of standards not represented by nominal values of mass of denominations of 1, 2 and 5 x 10n can be certified as standards but the appropriate tolerance must be determined.

B2.0 Care and maintenance of mass standards

When not in use, standards should be covered or stored in their carrying cases. These cases must have appropriate compartments for each weight of a series. The interior of the case must be such that the standards are protected against any wear, abrasion or shock that may be encountered during transportation.

When stored, carrying cases should be kept off the floor to protect them from dampness, which can affect the stability of the standards.

Standards must be protected from drafts and dust.

Stainless steel reacts with the chrome salts used in the manufacturing process of chamois, especially if the chamois is left in contact with the standards over a long period of time. Usually, a chamois is kept with the standards in a closed box, where it may remain for months at a time. Any new chamois must therefore be washed with soap and water, rinsed thoroughly and dried before use.

B2.1 Adjustment of mass standards

When field standards being calibrated or verified are not within 2/3 of their applicable tolerance, they are adjusted. The adjustment is made so that the standard's value is now within 1/3 of the applicable tolerance.

Inspector weights are adjusted using lead because it is malleable and its density is very high (11 340 kg/m3). The adjustment cavity is then closed and a MC inspection mark is applied. Whenever large quantities of adjusting material are added, the adjusting material should be of the same material as that from which the standards were fabricated.

B2.2 Cleaning and refurbishing standards

Inspector weights are cleaned by scrubbing off excess rust, flaking paint, etc. Oil and dirt may be removed by using a cloth moistened with mineral spirits; in this case, the cleaning solution must be allowed to evaporate over a 24-hour period prior to calibration taking place.

When a weight is made of a material that oxidizes such as cast iron, it is important that the surface finish be disturbed as little as possible to maintain weight stability. Once the surface acquires its initial oxidation coat, any further corrosion significantly slows. Therefore, the less the new surface is exposed to fresh oxidation, the more stable the standard. It is also important to use a surface finish with good flow and self-adhesive properties to fill minor gaps, seal the surface, and securely bond with previous coats of paint.

B2.2.1 New cast iron standards

New standards must be kept unfinished for two weeks prior to any finishing material being applied.

Before painting, new standards should be lightly cleaned with a wire brush to loosen surface rust, wiped with a cloth moistened with mineral spirits to remove dust, loosened rust, surface oils, etc., and then painted with a primer/sealer and allowed to dry thoroughly.

Two coats of metallic rust-preventative paint (aluminum based) should be applied with a brush or sprayed in very thin layers and then the required markings should be applied for identification.

A coating of paint is only recommended once for the bottom of standards greater than 5 kg and having recessed bottoms.

When two different colours are used to differentiate between avoirdupois and metric weights, it is recommended that metric standards be painted with gold aluminum paint and avoirdupois standards with silver aluminum paint.

The standard should be allowed to dry overnight, as a minimum, prior to calibration to ensure that the solvents have completely evaporated from the paint.

It is good lab practice to test the paint on one standard first and then test for adhesion first before applying to the full set.

B2.2.2 Refurbishment of cast iron standards

Under no circumstance must a cast iron standard be sandblasted. Regular maintenance as described below will ensure that the surface coatings do not become excessively thick.

As a minimum, the standard must be:

A coating of paint is recommended for the bottom of standards greater than 5 kg and having recessed bottoms. When two different colours are used to differentiate between avoirdupois and metric weights, it is recommended that metric standards be painted with gold aluminum paint and avoirdupois standards with silver aluminum paint.

The standard should be allowed to dry overnight, as a minimum, prior to calibration to ensure that the solvents have completely evaporated from the paint.

Date modified: