Convert Millimeters of Mercury to Technical Atmospheres
Convert Millimeters of Mercury (mmHg) to Technical Atmospheres (at) instantly and accurately.
Conversion Formula
at = mmHg × 0.00135951
About Millimeters of Mercury
One millimetre of mercury (mmHg) = pressure from 1 mm of mercury at 0°C and standard gravity = 133.322 Pa. Clinical medicine worldwide uses mmHg for blood pressure (normal ~120/80 mmHg) and for gas partial pressures in physiology: arterial O₂ ~95-100 mmHg; CO₂ ~40 mmHg; alveolar O₂ ~104 mmHg. Ophthalmologists measure intraocular pressure in mmHg (normal 10-21; glaucoma risk above 21). Vacuum equipment ratings are also given in mmHg. 760 mmHg = 1 atm. 1 mmHg = 133.322 Pa.
About Technical Atmospheres
One technical atmosphere (at) = exactly 1 kgf/cm² = 98,066.5 Pa ≈ 0.968 standard atmospheres. The metric technical pressure unit used in pre-SI European and Japanese engineering for boilers, hydraulic cylinders, and compressed gas systems. A steam boiler at 10 at operates at 0.981 MPa; hydraulic presses are rated at 200-600 at. Still used parenthetically in old German and Japanese machinery manuals and standards (DIN 1301-3 legacy). Converts simply from kgf/cm²: 1 at ≡ 1 kgf/cm². 1 at = 98,066.5 Pa.
Quick Reference Table
| Millimeters of Mercury (mmHg) | Technical Atmospheres (at) |
|---|---|
| 1 mmHg | 0.00135951 at |
| 2 mmHg | 0.00271902 at |
| 5 mmHg | 0.00679755 at |
| 10 mmHg | 0.0135951 at |
| 25 mmHg | 0.0339878 at |
| 50 mmHg | 0.0679755 at |
| 100 mmHg | 0.135951 at |