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The technical system of units (originally French Système the Méchaniciens ) is an outdated system of units , which in addition to the base units meter and second as a base size , the power to the unit kilogram force used.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: ${\ displaystyle g _ {\ mathrm {N}}}$

{\ displaystyle 1 \, \ mathrm {kp} = g _ {\ mathrm {N}} \ cdot 1 \, \ mathrm {kg} = 9 {,} 80665 \, \ mathrm {kg \, m \, s} ^ {-2} = 9 {,} 80665 \, \ mathrm {N}}

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
force	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
pressure	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.

[cardarelli-1] 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).

[Dobrinski-2] Paul Dobrinski, Gunter Krakau, Anselm Vogel: Physics for engineers . Springer, 2003, ISBN 3-519-46501-9 , pp. 690 ( limited preview in Google Book search).

[3] Paul Profos, Tilo Pfeifer: Handbook of industrial measurement technology. Oldenbourg, Munich 1994, ISBN 3-486-22592-8 , p. 626.