Technical measurement system
The technical system of units (originally French Système the Méchaniciens ) is an outdated system of units , which in addition to the base units meter and second as a base size , the power to the unit kilogram force used. Internationally used abbreviations for the measurement system are MKpS , MKfS or MKS (from French mètre-kilogramme-poids-seconde or mètre-kilogramme-force-seconde ). The abbreviation MKS, however, also stands for the MKS system , which uses the mass in kilograms as the base quantity instead of the force in kilograms .
disadvantage
While today a clear distinction is made between mass as a property of a body and its location-dependent weight force , historically the kilopond was referred to as the kilogram and it was only later that a distinction was made between a mass kilogram (today: kilogram) and a force kilogram (today: kilopond). A kilopond was originally defined by the weight of a mass of one kilogram. Since the gravitational acceleration of the earth is slightly different locally, there are locally different values for the unit kilopond. For this reason, a geographical latitude of 45 degrees and sea level was initially set as the location , then in 1902 the standard acceleration value was set as the standard value for the acceleration due to gravity.
Further disadvantages of the measurement system are inconsistent conversion factors, for example the unit horsepower (1 PS = 75 kp · m / s) and the lack of connection to units of electrical , magnetic or thermodynamic quantities .
The kilopond has been inadmissible by law in Germany since January 1, 1978 for specifying the force. Units derived from this were replaced by SI units . A kilopond can be converted by multiplying it with the standard acceleration of fall:
units
The following units, among others, are derived from the base units
Physical size | Unit name | Unit symbol | definition | SI equivalent |
---|---|---|---|---|
length | meter | m | - | |
time | second | s | - | |
force | Kilopond, strength kilogram | kp, kg, kg ^{*} , kg _{p} , kg _{f} , kgf | - | 9.806 65 N |
Pond | p | 1000 p = 1 kp | 9.806 65 mN | |
Dimensions | Hyl, technical mass unit | hyl, TME | 1 hyl = 1 kp · s² / m | 9.806 65 kg |
pulse | Kilopond second | kps | 1 kps = 1 kps | 9.806 65 kg m / s |
Work energy torque |
Kilopond meter, meter kilopond | kp m | 1 kp m = 1 kp m | 9.806 65 J |
power | Kilopond meters per second | kp m / s | 1 kp m / s = 1 kp m / s | 9.806 65 W. |
Poncelet | p | 1 p = 100 kp m / s | 0.980 665 kW | |
Horsepower | PS | 1 PS = 75 kp · m / s | 0.735 489 75 kW | |
pressure | Technical atmosphere | at | 1 at = 1 kgf / cm² | 980.665 hPa |
Meters of water column | mH _{2} O, mWS | 10 mH _{2} O = 1 kgf / cm² | 98.0665 hPa |
Individual evidence
- ^ ^{A } ^{b} François Cardarelli: Encyclopaedia of Scientific Units, Weights and Measures: Their Si Equivalences and Origins . Springer Science & Business Media, 2003, ISBN 1-85233-682-X , p. 19 ( limited preview in Google Book search).
- ^ Paul Dobrinski, Gunter Krakau, Anselm Vogel: Physics for engineers . Springer, 2003, ISBN 3-519-46501-9 , pp. 690 ( limited preview in Google Book search).
- ^ Paul Profos, Tilo Pfeifer: Handbook of industrial measurement technology. Oldenbourg, Munich 1994, ISBN 3-486-22592-8 , p. 626.