Keywords Weights & Measures

To implement metric conversion the government established a Preparatory Commission in 1971, later called Metric Commission Canada. The commission's role was to ensure a planned and co-ordinated conversion in all sectors of the Canadian economy and to disseminate information on metric conversion. Beginning in 1973 the commission organized over 100 sector committees, with members from national associations and major organizations representing business and industry, consumers, labour, health, education and government. Each sector committee was responsible for preparing a sector conversion plan and monitoring its implementation. The commission as a whole approved sector conversion plans developed through consensus.

The process of replacing imperial units with SI units in all kinds of documents, measuring devices, manufacturing processes, products and packages involved a countless variety of tasks. The technical basis for the change to SI units was established by 2 national standards of Canada, the International System of Units (SI) and the Canadian Metric Practice Guide, first published in 1973 by the Canadian Standards Association and approved by the Standards Council of Canada.

After choosing appropriate SI units, practical approaches to implementation were debated by sector committees, with each sector determining policies and strategies to suit its interests. Soft conversion (arithmetical conversion of pre-existing measurement values) versus hard conversion (round, rational values in metric units, possibly requiring physical change in product size) was a major issue. The use of both imperial and metric measurements was another area of controversy. Dependence on the US for many parts and products was a constraint for many sectors. The dedicated efforts of Canadian industry allowed conversion to proceed with few major problems, although it took 2-5 years longer than planned.

Education and public-awareness programs were important considerations to ensure public understanding and acceptance of the change to metric units. With the co-operation of all provinces, schools prepared to teach mainly the metric system. A series of metric conversion events exposed the public to simple metric units in everyday life; extensive information campaigns accompanied each change. The first such event was the announcement of temperature in degrees Celsius in weather forecasts beginning 1 April 1975. From September 1975 rainfall and snowfall were quoted in millimetres and centimetres, respectively. The next significant change (September 1977) was the introduction of road signs showing distances in kilometres and speed limits in kilometres per hour. Concurrent with this change, cars with speedometers and odometers graduated in metric units were produced.

In January 1979 service stations started pricing and dispensing gasoline and diesel fuel in litres. In December 1980 (the cutoff date for using imperial length units) fabrics and home furnishings were required to be advertised and sold only by the metre and centimetre. Conversion of weighing scales in retail food stores created political controversies. After 3 pilot areas (Kamloops, Peterborough and Sherbrooke) completed scale conversion in the summer of 1979, national conversion was postponed by the government of the day, but was resumed in January 1982. Cutoff dates were established for different areas, extending up to December 1983. After that, store-weighed food items could be priced and advertised only by kilogram or 100 gram quantities and sold only in metric units. Conversion involved some 35 000 retail food stores across Canada. Steadily metric units became normal for most products and services. However, metric units did not receive support in real estate or in sports (except track and field and swimming).

Metric conversion proceeded voluntarily in many sectors, but federal and provincial legislative action was required in some. Regulations on the use of metric units for WEIGHTS AND MEASURES in retail trade were established and enforced by the government for the protection of consumers and retailers against unfair practices and confusion in comparing products. Even so, the government did not escape criticism for imposing mandatory use of metric units to the exclusion of old units. Opponents of metric conversion pointed to the costs at a time of inflation and economic weakness, the danger of being out of step with the US and the invasion of a foreign language of measurements upon a Canadian heritage bound to imperial measurements. Some challenged metrication through the courts.

The Conservative government of Brian Mulroney reaffirmed the commitment to metric but revoked the required use of metric alone in some cases, eg, gasoline and diesel fuels and home furnishings. In 1985 some small businesses were exempted from the requirement to install metric scales. Defendants of metric measurements have cited many benefits besides export trade and international standardization. SI is simple because of its decimal nature and the absence of a multiplicity of units with conversion factors. The universality of SI symbols (regardless of language) and the convenience of having a single unit for a physical quantity made communications clearer. Upgrading of many technical standards and rationalization of product sizes and containers were side benefits. All these led to long-term cost savings, despite initial conversion expenses. In the final analysis, pressures of technology and of the marketplace made metric conversion inevitable for Canada.

Author N. GANAPATHY

Links to Other Sites
Measuring Success one Standard at a Time
A brief history of Canada’s conversion to the metric system of measurement. From the Standards Council of Canada.

Weights and Measures Act
The full text of the "Weights and Measures Act" from the Department of Justice Canada website. Click on Schedules I, II, III, and IV for lists of units of measurement.

One to nine and beyond
An online guide to the SI system of units and related numerical topics. From the International Development Research Centre.

Why metric makes sense
A CBC Radio discussion in favour of Canada switching to the metric system of measurement.