M-24—Secondary indicators

Category: Mass
Bulletin: M-24 (rev. 3)
Document(s): Specifications Relating to Non-Automatic Weighing Devices (1998), sections 18 and 59, Weights and Measures Regulation 143
Issue Date:
Effective Date:
Supersedes: M-24 (rev. 2)


Table of contents


1.0 Purpose

The purpose of this bulletin is to specify when a secondary indicator is required for scale installations and the requirements for such an indicator. A secondary indicator is any indicator without metrological functions that is used to replicate the display of the primary indicator. Secondary indicators are sometimes referred to as scoreboards.

2.0 Background

Section 59 of the Specifications Relating to Non-Automatic Weighing Devices (1998) (SRNAWDS) and section 143 of the Weights and Measures Regulations require that the indications of the primary indicator be clearly read by any party to the transactions (operator or customer). When a single indicator is not sufficient to allow both the operator and the customer to see the indications, a secondary indicator is required. A secondary indicator is only required for direct sale transactions, that is, transactions during which both parties are present.

3.0 Application

3.1 Although secondary indicators are more commonly used as part of vehicle scale installations, they are also used as part of many other installations where they may be appropriate and required to comply with section 59 of the SRNAWDS and section 143 of the Regulations. In order to ensure accuracy of all secondary indications, the provisions of this bulletin must be followed.

3.2 If a secondary indicator is required to address the requirements for customer visibility, a suitable secondary indicator must be installed and available for use before an initial inspection can be performed. This requirement applies to all initial inspections of new or altered installations, except the initial inspection of a replacement indicator for an existing installation.

3.3 In addition to the requirements in section 3.2 above, initial inspections of new or altered vehicle scale installations, not including the initial inspection of a replacement indicator for an existing installation, are subject to the following:

4.0 Requirements

Although the secondary indicator need not be approved, it must comply with the relevant requirements for agreement for registration in standard test procedure 17: Agreement of Registration of the Field Inspection Manual for Non-Automatic Weighing Devices or the applicable standard test procedure of the Field Inspection Manual for Automatic Weighing Devices.

5.0 Markings and indications

5.1 Subject to section 5.2, if the weighing system can switch between weighing modes (i.e. gross, net), the secondary indicator must indicate the weighing mode in use, unless the primary indicator is equipped with an automatic means for printing gross, net and tare weights and a copy of the printed receipt is provided to the customer. In this case, the secondary indicator does not have to indicate the weighing mode.

5.2 Secondary indicators for point of sale systems may display gross weight even though the printed receipt shows net weight. A weighing mode annunciator is not required as long as a printed receipt showing net weight is provided to the customer.

5.3 Secondary indicators need not be marked with Max and e. However, these markings must continue to appear near the primary display.

5.4 Secondary indicators must display live, free floating weight indications at all times while weighing is taking place. However, secondary indicators may be used for other purposes such as advertising and calculating axle load weights. When used for these purposes, the load receiving element must be empty and at gross load zero indication. It is also acceptable to use the scale in this manner while it is being loaded or unloaded, but before a final stable weight indication has been achieved, if provisions are made to ensure a zero load condition prior to weighing and the final gross weight is a true live weight.

5.5 The installation or the replacement of an unapproved secondary indicator does not require an inspection.

5.6 The installation or the replacement of an approved indicator, the functions of which have all been disabled or removed to serve as a secondary indicator, does not require an inspection. In such a case, the indicator ceases to be of an approved type, must not be marked with an approval number or inspection mark and is simply used to indicate the weight information received from the primary indicator.

6.0 Revisions

The purpose of this revision is to:

The purpose of revision 2 was to:

The purpose of revision 1 was to:

Date modified: