Weights and Measures Act
Version of the schedule from 2005-08-31 to 2017-05-04:
SCHEDULE I(Section 4)Units Based on the International System of Units
SCHEDULE I(Section 4)Units Based on the International System of Units
PART I
Basic Units of Measurement
| Basic Unit | Symbol | Definition | |
|---|---|---|---|
| 1 | metre | m | the unit for the measurement of length, being a length equal to the distance travelled by light in a vacuum during 1/299 792 458 of a second |
| 2 | kilogram | kg | the unit for the measurement of mass, being a mass equal to the mass of the international prototype of the kilogram established in the year 1889 by the First General Conference of Weights and Measures and deposited at the International Bureau of Weights and Measures |
| 3 | second | s | the unit for the measurement of time, being the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom |
| 4 | ampere | A | the unit for the measurement of electric current, being a constant current that, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section and placed one metre apart in vacuum, would produce between those conductors a force equal to 2 x 10-7newton per metre of length |
| 5 | kelvin | K | the unit for the measurement of thermodynamic temperature, being the fraction 1/273.16 of the thermodynamic temperature of the triple point of water |
| 6 | candela | cd | the unit for the measurement of luminous intensity, being the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 x 1012 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian |
| 7 | mole | mol | the unit for the measurement of the amount of substance, being the amount of substance of a system that contains as many elementary entities as there are atoms in 0.012 kilogram of carbon 12 |
PART II
Supplementary Units of Measurement
| Supplementary Unit | Symbol | Definition | |
|---|---|---|---|
| 1 | radian | rad | the unit for the measurement of a plane angle, being the angle with its vertex at the centre of a circle and subtended by an arc of the circle that is equal in length to its radius |
| 2 | steradian | sr | the unit for the measurement of a solid angle, being the angle with its vertex at the centre of a sphere and subtended by an area on the spherical surface equal to that of a square with sides equal in length to the radius |
PART III
Derived Units of Measurement
| Derived Unit | Symbol | Definition | |
|---|---|---|---|
| 1 | newton | N | the force that, when applied to a body having a mass of one kilogram, gives the body an acceleration of one metre per second per second |
| 2 | joule | J | the work done when the point of application of a force of one newton is displaced a distance of one metre in the direction of the force |
| 3 | watt | W | the power that produces energy at the rate of one joule per second |
| 4 | hertz | Hz | the frequency of a periodic phenomenon of which the periodic time is one second |
| 5 | coulomb | C | the quantity of electricity transported in one second by a current of one ampere |
| 6 | volt | V | the unit of electric potential difference and electromotive force, being the difference of electric potential between two equipotential surfaces of a conductor that is carrying a constant current of one ampere when the power dissipated between these surfaces is equal to one watt |
| 7 | farad | F | the capacitance of a capacitor between the equipotential surfaces of which there appears a difference of potential of one volt when the capacitor is charged by a quantity of electricity equal to one coulomb |
| 8 | henry | H | the inductance of a closed circuit in which an electromotive force of one volt is produced when the electric current in the circuit varies uniformly at a rate of one ampere per second |
| 9 | ohm | Ω | the electric resistance between two points of a conductor when a constant difference of potential of one volt, applied between these two points, produces in the conductor a current of one ampere and the conductor itself is not the seat of any electromotive force |
| 10 | weber | Wb | the magnetic flux that, when linking a circuit of one turn, produces in that circuit an electromotive force of one volt as the flux is reduced to zero at a uniform rate in one second |
| 11 | tesla | T | the magnetic induction that is equal to one weber per square metre |
| 12 | lumen | lm | the luminous flux emitted in a solid angle of one steradian by a point source having an intensity of one candela |
| 13 | lux | lx | the illuminance produced by a flux of one lumen uniformly distributed over one square metre |
| 14 | pascal | Pa | the pressure (or stress) produced when a force of one newton is applied to an area of one square metre |
| 15 | var | var | the reactive power at the two points of entry of a single-phase, two-wire circuit when the product of the root-mean-square value in amperes of the sinusoidal current by the root-mean-square value in volts of the sinusoidal voltage and by the sine of the angular phase difference by which the voltage leads the current is equal to one |
| 16 | becquerel | Bq | the activity of radionuclides that is equal to one per second |
| 17 | gray | Gy | the absorbed dose of ionizing radiation that is equal to one joule per kilogram |
| 18 | siemens | S | the electric conductance between two points of a conductor when a constant current of one ampere in the conductor produces a difference of potential of one volt between these two points and the conductor itself is not the seat of any electromotive force |
PART IV
Customary Units of Measurement Used with the International System
| Customary Unit | Symbol | Definition |
|---|---|---|
| minute | min | 60 seconds |
| hour | h | 3 600 seconds |
| day | d | 86 400 seconds |
| degree (of arc) | ° | p/180 radianFootnote for PART IV Customary Units of Measurement Used with the International System* |
| minute (of arc) | ′ | p/10 800 radianFootnote for PART IV Customary Units of Measurement Used with the International System* |
| second (of arc) | ″ | p/648 000 radianFootnote for PART IV Customary Units of Measurement Used with the International System* |
| litre | L, l or l | 1/1 000 cubic metre |
| tonne or metric ton | t | 1 000 kilograms |
| hectare | ha | 104 square metres |
| millilitre | mL, ml or ml | 1/1 000 litre |
| degree Celsius | °C | an interval of 1°C = an interval of 1 kelvin; a temperature of 0°C corresponds to 273.15 kelvins |
Return to footnote *p is the ratio of the circumference to the diameter of a circle.
PART V
PrefixesFootnote * for Multiples and Submultiples of Basic, Supplementary and Derived Units of Measurement
| Prefix | Symbol | Definition |
|---|---|---|
| yotta | Y | 1024 |
| zetta | Z | 1021 |
| exa | E | 1018 |
| peta | P | 1015 |
| tera | T | 1012 |
| giga | G | 109 |
| mega | M | 106 |
| kilo | k | 103 |
| hecto | h | 102 |
| deca | da | 101 |
| deci | d | 10-1 |
| centi | c | 10-2 |
| milli | m | 10-3 |
| micro | µ | 10-6 |
| nano | n | 10-9 |
| pico | p | 10-12 |
| femto | f | 10-15 |
| atto | a | 10-18 |
| zepto | z | 10-21 |
| yocto | y | 10-24 |
Return to footnote *Not applicable to the basic unit “kilogram” but applicable to the one thousandth submultiple of that unit, namely the “gram (g)”.
- R.S., 1985, c. W-6, Sch. I
- SOR/86-420
- SOR/2005-277, ss. 1, 2
- Date modified: