The metric conversion was the process of switching from the British imperial system (yard, gallon, pound, Fahrenheit, etc.) to metric units (metre, litre, kilogram, Celsius, etc.). The process was met with quite some resistance from both the public and the Government and it took many years for the new standards to settle. Even now, both systems are mixed together and certain measurements are still done in imperial units, such as height.
In the 1960s, with rapidly advancing technology and expanding worldwide trade, the need for an international measurement system became increasingly apparent. The change was expected to bring benefits like export trade and international standardization. The simplicity of a metric system because of its decimal nature and the absence of a multiplicity of units with conversion factors was another advantage. And last, but not least is the universality of metric symbols (regardless of language).
It all began with the 1970 “White Paper on Metric Conversion in Canada” and the "Weights and Measures Act" amended by Parliament in 1971. These mandated the use of the measurement system based on metric units for all measurement purposes, including legislation. The 1971 "Consumer Packaging and Labelling Act" was issued to require that metric units be shown on labels of most consumer products.
In 1971 the "Metric Commission Canada" was established to come up with the action plan and organize the process. It required the effort of many committees and members representing business, industry, consumers, labour, health, education and government. Each decision was to be approved by a commission as a whole.
In 1973 the international system of units (SI) was approved by the Standards Council of Canada. There were certain practical issues though. One of the major ones was the decision between the soft conversion (arithmetical conversion of pre-existing measurement values) versus hard conversion (round, rational values in metric units, possibly requiring a physical change in product size). Dependence on the United States for many parts and products was another constraint that called for mixed-use of both imperial and metric measurements.
Education and public-awareness programs were important steps to make sure the general public is not facing major issues with the change. Here are some metric conversion events that were accompanied by the extensive information campaigns.
The scale conversion was done in three pilot areas (Kamloops, Peterborough and Sherbrooke) first, in the summer of 1979. The national conversion was postponed and only resumed in 1982, though.