Revoked — SGM-1 — Relating to the Design, Composition, Construction and Performance of Electronic Computing Automatic Weighing Devices

These specifications were revoked and their requirements integrated in the Weights and Measures Regulations with the regulatory amendments SOR/2012-28, which came into force on May 1st, 2012.

Amendments to the Weights and Measures Regulations (Integration of SGM-1 and SGM-3 Specifications) (SOR/2012-28)

Category: Mass
Specification: Revoked—SGM-1 Relating to the Design, Composition, Construction and Performance of Electronic Computing Automatic Weighing Devices
Date: 1999-08-17

Table of Contents

Short Title

1. These specifications may be cited as the Weights and Measures Specifications SGM-1.

Authority

2. These specifications are established pursuant to section 13 of the Weights and Measures Regulations, C.R.C., c.1605. (SI/98-27)

Interpretation

3. In this specification, "scale" means any weighing machine to which these specifications apply. (SI/98-27)

Application

4. Except as may otherwise be allowed by a Notice of Approval these specifications apply to any electronic digital indicating computing scale capable of use in trade with electronic components that has minimum increments of registration of 0.01 pound or less and 10 grams or less; these specifications are to be read in conjunction with the Weights and Measures Act and Weights and Measures Regulations.

Motion Detection

5. Except as may otherwise be allowed by a Notice of Approval, a scale shall incorporate a non-operator controlled motion detector to prevent the recording of a weight signal until the load receiving element is stable within + 1 minimum increment of registration.

5.1 The load receiving element shall be stable as required by 5., at least 0.4 second before a weight signal is recorded.

5.2 The motion detector and automatic zero control circuits shall be interlocked so that use of the latter is inhibited during operation of the former.

Platter Lock

6. A scale incorporating a platter locking system shall be designed and constructed such that the system does not interfere with the zero balance display, and it shall be inoperative until the load receiving element is stable as in 5.

Electronic Indicators

7. The contrast between any digital display and the background shall have a ratio equal to or greater than 4 to 1.

7.1 A scale shall incorporate a test system for verifying that all display segments are neither continuously on nor off; such test system shall permit verification of display segments without the need for any tools or by a self-verifying automatic system that indicates the occurrences of any failure.

Free Floating Weight Signal

8. In order to allow for adjustment of commodities to a desired weight before the settled weight is used for computation, the weight signal used for computing the total price must be free floating until entry for computation.

Weight Units

9. Associated with any digital weight registration there shall be suitably located an appropriate name, symbol or abbreviation for the unit of measurement registered.

Capacity Indication

10. No digital indicating element or recording element shall register any value when the load exceeds the rated capacity of the scale by more than 10 minimum increments of registration.

Customer Indication

11. Exempt as may otherwise be allowed by a Notice of Approval, any scale equipped with a digital registration for the operator shall have duplicate displays for the customer.

Construction and Design to Facilitate Inspection

12. Except as may otherwise be allowed by a Notice of Approval, means shall be provided to seal only the coarse zero and span adjustment controls so that all other components and adjustments are readily accessible without breaking the seal; such means shall be readily observable upon inspection without the necessity of disassembling any part requiring the use of mechanical means separate from the scale.

Zero

13. When a scale displays a weight value less than zero, the total price indicator shall not display any value and recording elements shall be interlocked to inhibit the recording of negative weight values.

13.1 The maximum zero range of the type which may be adjusted from the scale exterior shall not exceed 4 per cent of rated scale capacity; unless operable only by a detachable tool, when activated, such adjustment mechanism shall only return the scale to a zero balance condition.

13.2 Automatic means to maintain a digital zero balance condition shall be non-operator controlled and the maximum load that may be placed on the load receiving element, with the scale indicating zero and "rezero" without indicating a weight value, shall be a mass equal to 0.6 of a minimum increment of registration.

13.3 The maximum zero range of an automatic means of maintaining zero shall not exceed 4 per cent of rated scale capacity.

Tare

14. The tare mechanism shall operate only in the direction of under-registration with respect to the zero load balance condition of the scale, and a negative weight indication shall continue to be displayed when the load receiving element is empty.

14.1 When the tare mechanism is functioning there shall be visual confirmation on or adjacent to the weight display that the tare mode is operating.

14.2 A scale may be equipped with full scale tare; however, the gross weight shall not exceed the rated capacity of the scale within the limits given in paragraph 10.

14.3 A tare mechanism shall be self-cancelling, that is, when any net weight is added to the tare, the total is computed and the gross amount if removed from the scale, the weight indication shall return to a zero balance condition in accordance with regulation 183, unless the scale is in the pre-packing mode.

14.4 An automatic tare control shall be identified with the word "TARE", the letters "TR", or words or letters that convey the same meaning.

14.5 Except as may otherwise be allowed by a Notice of Approval, a tare entry shall only be erased from the scale memory with the removal of gross load from the weighing element; entry of another price per unit of weight, use of a "clear" mechanism or any other keying sequence shall not affect the tare entry.

14.6 A scale incorporating a tare mechanism shall incorporate a power failure interlock providing a means whereby temporary loss of power to the scale will prevent a further scale operation without requiring a very obvious reset operation; when there is a loss of power to a scale all means of indicating that the scale is in the tare mode shall extinguish and remain extinguished when power returns.

14.7 Except as may otherwise be allowed by a Notice of Approval, the minimum increment of tare shall be the same as the minimum increment of registration.

14.8 The use of any mechanism to convert units of measurement (for example, lb/kg switch) shall be inhibited when tare is entered in a scale, unless this mechanism converts all values of weight registration when activated.

Price Per Unit of Weight Indicator

15. Any scale other than one for pre-packing use shall clear all digital indication of total price and price per unit of weight, and shall extinguish the tare indication when either the commodity is removed from the weighing element or before another commodity is weighed and its price computed.

Pre-Packing Mode

16. When a scale is in the pre-packing mode there shall be a visual confirmation of this on both the operator and customer sides of the scale, whether by the legend "FOR PRE-PACKING USE" or words that convey the same meaning.

Level Indicating Means

17. A scale shall be equipped with a level indicating means which shall be readily observable without the necessity of disassembling any scale part requiring the use of mechanical means separate from the scale.

Registration of Monetary Value

18. Any registration of monetary value shall be in mathematical agreement with the quantity indication and unit price, and shall be "rounded off" to the nearest minimum unit as follows:

  1. when the figure next beyond the last figure or place to be retained is less than 5 the figure in the last place retained shall be kept unchanged;
  2. when the figure next beyond the last figure or place to be retained is 5 followed by any figure other than zero or is greater than 5, the figure in the last place retained shall be increased by one.

Withstanding Variations

19. Except as may otherwise be allowed by a Notice of Approval, the scale shall meet or exceed the performance criteria of the Weights and Measures Regulations, when tested after being calibrated and zeroed, under any possible combinations of the following operating conditions:

  • ambient temperature - 10°C to 40°C
  • relative humidity 10% to 95%

19.1 The weighing element shall withstand vertical forces to 150% of the rated capacity without affecting calibrations, and to 300% of rated capacity without permanent degradation.

19.2 A scale shall be capable of operating within ± 10% of its voltage rating and ± 2% frequency variation of its frequency rating.

Load Indication

20. For the same load kept on a scale, the difference between the indication obtained at the moment of placing the load and the indication obtained eight hours later shall not exceed the permissible acceptance limit of error for loads applied set out in Division 6 of the Weights and Measures Regulations.

20.1 The variation on returning to zero after the removal of a load which has remained on the scale for half an hour may not exceed one-half the finest digital increment of registration.

20.2 The no load indication shall not vary by more than one minimum increment of registration for a difference in ambient temperature of 5° C.

Miscellaneous

21. A scale shall meet or exceed the performance criteria prescribed by the Weights and Measures Regulations and by these specifications when tested at a constant ambient temperature, that is, a temperature that does not vary more than 5°C.

21.1 A scale shall meet or exceed the performance criteria of the Weights and Measures Regulations when scanned at a distance of 2 metres with

  1. a 460 MHz (commercial) 4 watt, hand-held communicator, and
  2. a 27 MHz (citizen's band) 4 watt, hand-held communicator.