Guide for the approval of large capacity weighing devices

Class approval policy

The Weights and Measures Act provides for the approval of any device or class, type or design of device. Before July 1, 1993, the Approval and Calibration Services Laboratory (ACSL) granted approval for use in trade of single devices, or designs and types of devices. These approvals are relatively restrictive in that the design, dimensions, and capacities of devices approved in this manner cannot be changed unless the applicant advises the ACSL of proposed changes and the applicable Notice of Approval is amended to allow these changes.

Since July 1, 1993, the ACSL issues Notices of Approval for specified classes of devices. CLASS approvals allow for significant changes in the design, dimensions and capacity of approved devices without having to revise the Notice of Approval.

Affected devices

CLASS Approvals apply to the Load Receiving Element (weighbridge) only. They do not apply to self-contained weighing devices with integral indicators, nor to Indicating Element components. There are currently five separate device classes covered by Class Approvals:

  1. Vehicle weighbridge—A vehicle load receiving element used for static weighing. Does not include portable wheel weighers.
  2. Railway weighbridge—A railway load receiving element used for static weighing. Includes combination railway/vehicle weighbridge.
  3. Tank or hopper—A tank or hopper load receiving element used for static weighing. May include devices used in a Discontinuous Totalizing Weighing System (Bulkweighers). Does not include any on-board weighing devices.
  4. Platform—A platform load receiving element used for static weighing. Does not include any on-board weighing devices.
  5. Scale system assembly—Other specialized large capacity load receiving elements used for static weighing not included in one of the classes above. Examples include paper roll scales, coil scales or ingot scales. These approvals are not intended to market weighing kits without load receiving elements.

Any Non-automatic Weighing Device with a configured and inspected capacity of greater than 10 000 kg is automatically eligible to be covered by a CLASS Approval.

A Non-automatic Weighing Device with a configured and inspected capacity of 10 000 kg or less may be covered by a CLASS Approval if it is of such a size or configuration that it cannot be readily tested in the laboratory. The ACSL should be contacted for more information.

The approval for each of these classes of large capacity weighing devices applies only to the load receiving element. A primary weight indicator used with a large capacity weighing device which is class approved must be approved separately by the ACSL before the associated weighing system is initially inspected and certified by a Measurement Canada inspector or Authorized Service Provider.

The load sensing elements of a CLASS approved large capacity weighing device are not included in its CLASS approval.

Previously approved large capacity weighing devices

This policy does not affect the status of a large capacity weighing device previously approved. Where a design or type of device is approved for use in trade, its trade use may continue, and devices of that design or type may continue to be sold for use in trade. However, the holder of a Notice of Approval (manufacturer, importer or dealer) for a design or type of device may request a CLASS approval for that design or type of device. In this instance, all devices of that class may be sold for use in trade and any new device must be marked with the approval number issued for that class of device.

Applying for a CLASS approval

As of July 1, 1993, a new device of an affected class which has not previously received full or conditional approval, is not initially inspected unless the manufacturer, importer or dealer holds a valid CLASS approval for the class of device involved. A manufacturer, importer or dealer must apply in writing to the ACSL for CLASS approval. Applicants must apply at least 90 days in advance of any anticipated initial inspection of a device, if the criteria for CLASS approval outlined below has been satisfied. Otherwise, obtaining CLASS approval may take much longer.

When applying for a CLASS approval, a Type Approval Request Form must be completed and submitted to the ACSL.

To receive a CLASS approval, applicants must possess non-conditional approval for at least one device in the class for which they are applying, with a capacity over 10 000 kg.

If the applicant for CLASS approval has not previously been issued a full approval for a large capacity device, a conditional approval (a "D" approval, see bulletin GEN-04) will be issued upon application if the device must be installed for use in trade in order to complete approval testing. The conditional approval will be upgraded to a full approval upon successful completion of approval testing. No conditional approval will be issued if the device can be evaluated without the device being installed for use in trade. In this case, approval testing will be completed as normal before a full approval is issued.

Once full approval has been granted, the applicant may then proceed to apply for a CLASS approval.

Issuance of a CLASS approval

A CLASS approval for a large capacity weighing device will be issued to a designated organization and is valid for an indefinite period of time unless it is revoked for due cause.

Once in receipt of a CLASS approval, it is the holder's responsibility to mark each subsequently installed weighing device with the approval number that appears in the applicable Notice of Approval for that class. Marking shall be carried out in accordance with the applicable requirements of the Weights and Measures Regulations or Specifications Relating to Non-automatic Weighing Devices (1998), where applicable.

Initial inspection of a Class approved weighing machine

A weighing machine whose load receiving element is class approved will be initially inspected in much the same manner as non-class approved devices. A copy of the standard inspection test procedures is available on request from any Measurement Canada District Office.

The certified load capacity is the maximum known test load applied to the scale during the initial inspection. The certified load capacity may be increased at any subsequent inspection where the device is tested and certified with a greater known load. A class approved scale whose design capacity exceeds 10 000 kg must be initially inspected to at least 10 000 kg otherwise the scale must be covered by an individual type approval before it may be used in trade.

It is the responsibility of the party requesting the initial inspection to arrange for all necessary test weights, equipment and dead load needed to test the scale to the desired certified capacity. Substitution of test weights with dead load as necessary, is permitted. A Measurement Canada inspector or Authorized Service Provider performing an initial inspection will witness the testing of the scale at any requested load which does not exceed the manufacturer's rated maximum load marked on the load receiving element. The Measurement Canada inspector or Authorized Service Provider will ensure that the indicator has been marked with the certified capacity, does not display a weight value above 105% of the certified load capacity, and will seal the means of adjustment of the indicator. If the owner of a large capacity weighing device subsequently wishes to have the certified capacity of his scale changed, the owner must contact the nearest Measurement Canada District Office or Authorized Service Provider to arrange for another inspection.

CLASS Approval authorization letter (CAAL)

If holders of a CLASS approval wish to use their CLASS approval to build a device with a capacity of 10 000 kg or lower, they must submit an Application for Type Evaluation Testing If this application is accepted, a CLASS Approval Authorization Letter (CAAL) will be issued outlining the parameters and installation location of the device. A CAAL is required for each device 10 000 kg or under for which CLASS approval holders wish to use their CLASS approval.

CAALS will only be issued in the event that the ACSL is unable to test the device due to its dimensions or design. CAALS will be issued at the sole discretion of the ACSL.