Metre–tonne–second system of units
- For a topical guide to this subject, see Outline of the metric system.
The metre–tonne–second or mts system of units is a system of physical units. It was invented in France, hence the unit names sthène and pièze, and became its legal system between 1919 and 1961 ("décret" May 5, 1961, "Journal Officiel"). It was adopted by the Soviet Union in 1933, and abolished there in 1955. It was a coherent system of units, much as SI and the cgs system, but with larger units for industrial use. The cgs system on the other hand was regarded as suitable for laboratory use only.
The base units of the mts system are as follows:
- length: metre
- volume: cubic metre or litre
- 1 m3 ≡ 1 kL
- mass: tonne,
- 1 t = 103 kg = 1 Mg
- time: second
- force: sthène,
- 1 sn = 1 t·m/s2 = 103 N = 1 kN
- energy: sthene-metre = kilojoule,
- 1 sn·m = 1 t·m2/s2 = 103 J = 1 kJ
- power: sthene-metre per second = kilowatt,
- 1 sn·m/s = 1 t·m2/s3 = 103 W = 1 kW
- pressure: pièze,
- "System of Measurement Units". IEEE Global History Network. Institute of Electrical and Electronics Engineers (IEEE). Retrieved 2011-03-21.
- "Notions de physique - Systèmes d'unités" [Symbols used in physics - units of measure] (in French). Hydrelect.info. Retrieved 2011-03-21.