Laboratory manual for the evaluation of non-automatic weighing devices

Part 2, section 1—Marking

Table of contents


Reference

Sections 49 to 54 of the Specifications Relating to Non Automatic Weighing Devices (1998)

1.0 Marking – Generalities

Complete weighing devices and major components (indicating elements and load receiving/weighing elements) of devices tested separately must be marked with certain information in the manner required by the Specifications Relating to Non Automatic Weighing Devices (1998). Complete devices in the same housing or made of non detachable major components are only required to bear one series of markings. Major components of complete devices must be marked individually if they can be separated and interfaced (mixed/matched) to other major components to form a device. Major components submitted for approval evaluation individually are tested separately and are also required to be marked individually.

Remote (secondary) weight displays, slave modules such as printers, keyboards, cash registers and other similar modules that are used in conjunction with approved devices are not required to be marked if they perform no significant metrological functions.

1.1 Marking – Complete devices

This section applies to complete devices in the same housing or complete devices made of major detachable components interfaced together and not intended to be separated and used in conjunction with other individually approved major components to form different devices. For such devices, only one series of information is required.

The device must be marked with:

1.2 Marking – Indicating elements

This section applies to indicating elements that are evaluated and tested separately. Such indicating elements are either submitted to approval evaluation separately or are major detachable components of a complete device and are intended to be used in conjunction with approved and compatible weighing elements to form different devices.

The indicating element must be marked with:

1.3 Marking – Software

1.3.1 For software that is evaluated separate from hardware, the identifying information (manufacturer name, model number and approval number) must be visible on the video display terminal or printable when called up from the menu, or be continually displayed. For further information regarding the approval evaluation of software, the Specifications Relating to Metrological Software on Measurement Canada=s Web site must be consulted.

1.4 Marking – Load receiving/weighing elements

This section applies to weighing elements that are evaluated and tested separately. Such weighing elements are either submitted to approval evaluation separately or are major detachable components of a complete device and are intended to be used in conjunction with approved and compatible indicating elements to form different devices.

The weighing element must be marked with:

1.5 Marking – Load cells

The marking of load cells is not required at this time.

1.6 Marking – Readability, location and permanence

1.6.1 The required information must be complete, legible, accessible and durable. If necessary for clarity, there must be defining words or authorized symbols associated with the numbers (i.e., model numbers, temperature range, etc.). See the list of acceptable defining words and symbols in Appendix 2-A. It is recommended that the height of capital letters be at least 2 mm (OIML R76‑1).

1.6.2 The required information must be appropriately located. Markings may be on either a marking plate affixed to a permanent part of the device, on the device itself, or both. Information that identifies the device (manufacturer name or trademark, model, serial and approval numbers) should be grouped together. Max, "d" and "e" (if different from "d") must be marked near the weight display(s). See the Note below sections 1.1.8 and 1.1.9 for additional information.

1.6.3 The marking must be visible without having to remove a permanent part of the device or having to move or lift the device. Markings must be available with minimum effort and be accessible without disassembly requiring the use of special tools or equipment.

Acceptable locations
  1. Markings (and/or the marking plate) may be located on the top, sides or front of the device. Markings may be located beneath the platter and fastened to the scale structure if the platter is easily removable (small devices such as computing scales and bench scales).
  2. Weighing elements. The required information must be on a surface that is an integral part of the chassis. If the information is on a label or a plate, it must be permanently attached to the device. A plate may be riveted or welded but not affixed with bolts or screws.
  3. Weighing elements of large scales. Identification information for the weighing elements of vehicle, axle load, floor, livestock, railroad track and large hopper or tank scales must be located near the point where the signal leaves the weighing element (this would be the transverse lever on a mechanical scale and on, or near, the junction box on an above ground scale). In the case of built-in weighing elements (flush mounted), the required information can be placed on the scale chassis and be accessible by the removal of a cover plate.
Unacceptable locations

Under the scale; inside a cabinet; on the back of the device or indicating element if it is difficult to move and is likely to be located near a wall; marking plate affixed to the platter.

1.6.4 If Max, "d" and "e", if different from "d", are displayed electronically, such as on a video display terminal, then they must be adjacent to the weight display and continuously displayed when the system is in the weighing mode.

1.6.5 The lettering must be permanent. This requirement also applies to words and symbols for measurement units adjacent to the weight display and to words and symbols that identify or indicate the status of metrologically significant annunciators. Perform the test described in LG 1.01 and grade the permanence of marking.

1.6.6 Plates or other materials (decals, labels or badges) on which the required information is marked must be made of durable material and permanently affixed to the device so that they cannot be easily removed and affixed to another device. Perform the test described in LG-1.02.

1.7 Marking – Special applications

Certain device types are designed for specific applications. Such devices may incorporate features, perform certain functions or operate in a particular fashion that would not be acceptable for all applications. Since these devices may not meet all the usual requirements, their use is restricted to the specific applications for which they were designed. The device restriction must therefore be permanently and clearly marked adjacent to both the operator and customer weight displays.

Some examples:

Weight classifiers

Digital weight classifiers round weight values up to the next scale interval. They are designed to classify packages within price ranges for shipping, courier or postal applications. Weight classifiers would therefore not be appropriate for use in grocery store applications. Their use is restricted and they must be marked with the following: << Weight classification only >> or << Weight classifier >> or << Postal scale >>.

Industrial devices

Certain devices are designed for industrial applications. They do not incorporate features that are normally required for devices used in direct sales to consumers. For instance, they may not have a display for consumers; the tare feature may not comply with the requirements for devices used in direct sale applications, etc. These devices, if they resemble devices intended to be used in direct sale applications, must be marked as follows to indicate that they are designed for industrial use only: <<Not for use in direct sale to the public>> or similar language.

1.7.1 The device is marked with the appropriate restriction.

1.8 Marking – Operational controls, indications and features

The marking of operational controls such as keys, push buttons and switches that are strictly for operator use is not required by Measurement Canada. Keys that are visible only to the scale operator need only be marked to the extent that a trained operator can understand the function of each key. It is however recommended that internationally recognized words and symbols be used.

Annunciators that are "metrologically" significant must be marked with words or acceptable symbols. The following are some examples of "metrologically" significant annunciators: centre of zero, "net", "gross" and "tare" weight indications, identification of the weighing element in use on a multi-deck weighing system, the range selected on a manual multiple range device, etc..

1.8.1 Annunciators for metrologically significant features are clearly and permanently marked.

LG‑1.01 Permanence of the lettering

Purpose

This test is aimed at evaluating the permanence of the information to be marked on the device, or a major detachable element evaluated separately, in order to determine if it will withstand wear and cleaning. Markings are subjected to the following tests to simulate accelerated wear. The markings are then compared to a typical set of markings exhibiting various degrees of wear, graded from excessive unacceptable wear (1) to minimal effect (7).

Application

This test is to be applied to all mandatory markings including the manufacturer's name, the model and serial numbers, Max and "d", the unit of measurement associated with weight indications (kg, lb), to other words or symbols associated with metrologically significant annunciators, etc..

Test procedure

Attempts are made to remove the marked information, whether on a badge (plate) or on the device itself, using the following means:

  1. Rub over one letter of the marking twenty (20) times using an ink eraser in the same manner and with the same force as one would normally exert while erasing an inscription written with a ballpoint pen.

    Note: For consistency of application, the laboratories use Eberhard Faber ink eraser type # 101, but any blue, hard rubber eraser is acceptable.

  2. Clean (rub 20 times) with the following cleansers which are presumed to be readily available:

    1. Cleansing liquid and a damp cloth
    2. "Soft" household cleansing powder and a damp cloth
    3. Window cleansing fluids and a damp cloth

    Note: Any brand of cleansing powder is acceptable (such as Ajax and Comet), if, at a minimum, it contains an abrasive and a detergent/surfactant. For consistency of application, the laboratories use the Windex brand of product for the test in part B.3.

Interpretation of results

The information marked on the label is deemed to be permanent if, after the test, the label receives a grading of four (4) or higher (see the sample on the next page).

Figure 1: Samples of various degrees of wear

Figure 1: Samples of various degrees of wear
Description of Figure 1

Set of markings exhibiting various degrees of wear, graded from excessive wear (1) to minimal wear (7). At level 1 the markings are essentially completely worn to the point that it impossible to tell markings existed. At level 2 the markings are almost completely worn; it is possible to tell markings existed but not what the markings were. At level 3 the markings are heavily worn; it is possible to tell markings exist but most characters are not recognizable. At level 4 the markings are worn to the point that some characters are unrecognizable. At level 5 the markings are visibly worn but the characters are still recognizable. At level 6 the markings show signs of wear but the characters are still easily recognizable. At level 7 the markings barely show signs of wear; all characters are perfectly recognizable.

LG-1.02 Plate, decal – permanence of installation and durability of the material

Purpose

To determine whether the label bearing identification markings (manufacturer's name, model and serial numbers, approval number, initial inspection marks or label) is permanently affixed to the device.

Test procedure

An attempt is made to remove the specimen label(s) from the device by pulling it off or by prying off a metal badge that is only attached using adhesive. Any means of removal are allowed while a deliberate effort to conceal the removal is made. Such an attempt shall be made at either ‑10°C and 40°C or at the minimum and maximum operating temperatures specified by the manufacturer.

Interpretation of results

An identification label is deemed to be permanently affixed to the device if it cannot be removed from the device and installed on another device without exhibiting readily observable signs of tampering. Acceptable indications of tampering are the destruction of the badge by tearing, permanent or extensive wrinkling, or the repeated exposure of the word "void" upon removal of the badge.

Note 1 A plate that is riveted to the device is deemed to be permanently fastened if the part of the device to which it is attached is not removable.

Note 2 For information such as lb/kg, motion annunciator, centre of zero annunciator, tare/net annunciator, Max, "d" and "e" (if different from "d") near the weight display, etc. (other than the identification markings: manufacturer=s name, model, serial and approval numbers), a sticker that is sturdy and will not detach when subjected to the normal conditions of use of the device (heat, cold, humidity, cleaning) is acceptable. It does not have to be of the self-destructive type.

Note 3 Labels that tear when removed can often be removed without breakage by affixing clear packing tape or a clear adhesive sheet on the label prior to removal. If a label can be removed in this fashion it is considered a non-compliance.

Revision

Original document

Date modified: