| Kilogram-force per square centimetre | |
|---|---|
 Soviet-made pressure gauges using kgf/cm | |
| General information | |
| Unit of | Pressure |
| Symbol | kgf/cm, at |
| Conversions | |
| 1 kgf/cm in ... | ... is equal to ... |
| SI units | 98.06650 kPa |
| FPS units | 14.22334 psi |
A kilogram-force per square centimetre (kgf/cm), often just kilogram per square centimetre (kg/cm), or kilopond per square centimetre (kp/cm) is a deprecated unit of pressure using metric units. It is not a part of the International System of Units (SI), the modern metric system. 1 kgf/cm equals 98.0665 kPa (kilopascals) or 0.980665 bar—2% less than a bar. It is also known as a technical atmosphere (symbol: at).
Use of the kilogram-force per square centimetre continues primarily due to older pressure measurement devices still in use.
This use of the unit of pressure provides an intuitive understanding for how a body's mass, in contexts with roughly standard gravity, can apply force to a scale's surface area, i.e. kilogram-force per square (centi-)metre.
In SI units, the unit is converted to the SI derived unit pascal (Pa), which is defined as one newton per square metre (N/m). A newton is equal to 1 kg⋅m/s, and a kilogram-force is 9.80665 N, meaning that 1 kgf/cm equals 98.0665 kilopascals (kPa).
In some older publications, kilogram-force per square centimetre is abbreviated ksc instead of kg/cm.
| Pascal | Bar | Technical atmosphere | Standard atmosphere | Torr | Pound per square inch | |
|---|---|---|---|---|---|---|
| (Pa) | (bar) | (at) | (atm) | (Torr) | (lbf/in) | |
| 1 Pa | — | 1 Pa = 10 bar | 1 Pa = 1.0197×10 at | 1 Pa = 9.8692×10 atm | 1 Pa = 7.5006×10 Torr | 1 Pa = 0.000145037737730 lbf/in |
| 1 bar | 10 | — | = 1.0197 | = 0.98692 | = 750.06 | = 14.503773773022 |
| 1 at | 98066.5 | 0.980665 | — | 0.9678411053541 | 735.5592401 | 14.2233433071203 |
| 1 atm | ≡ 101325 | ≡ 1.01325 | 1.0332 | — | 760 | 14.6959487755142 |
| 1 Torr | 133.322368421 | 0.001333224 | 0.00135951 | 1/760 ≈ 0.001315789 | — | 0.019336775 |
| 1 lbf/in | 6894.757293168 | 0.068947573 | 0.070306958 | 0.068045964 | 51.714932572 | — |
1 at = 98.0665 kPa ≈ 0.96784 standard atmospheres
Pressure gauge from unknown source produced by ISGUS GmbH.
Pressure gauge from unknown source. Note the visual square instead of . (Olja means "oil" in Swedish)
Ambiguity of at
The symbol "at" clashes with that of the katal (symbol: "kat"), the SI unit of catalytic activity; a kilotechnical atmosphere would have the symbol "kat", indistinguishable from the symbol for the katal. It also clashes with that of the non-SI unit, the attotonne, but that unit would more likely be rendered as the equivalent SI unit, the picogram.
References
- Dorf, Richard C. (2003-11-24). CRC Handbook of Engineering Tables. CRC Press. ISBN 9780203009222.
- Suplee, Curt (2009-07-02). "Special Publication 811". NIST. Retrieved 2019-05-17.
- The NIST Guide for the use of the International System of Units, National Institute of Standards and Technology, 18 Oct 2011