Pressure Conversion Calculator (mmHg)
| Unit | Value |
|---|
Information:
Standard atmospheric pressure: 760 mmHg
1 mmHg ≈ 1 torr (slight difference at high precision)
mmHg is commonly used in medical settings for blood pressure measurements
Here’s a comprehensive table with all the essential information about pressure conversion, focusing on millimeters of mercury (mmHg):
| Unit | Equivalent in mmHg | Conversion Factor (to mmHg) |
|---|---|---|
| 1 mmHg | 1 mmHg | 1 |
| 1 inHg (inch of mercury) | 25.4 mmHg | 25.4 |
| 1 Pa (Pascal) | 0.00750062 mmHg | 0.00750062 |
| 1 kPa (Kilopascal) | 7.50062 mmHg | 7.50062 |
| 1 bar | 750.062 mmHg | 750.062 |
| 1 atm (atmosphere) | 760 mmHg | 760 |
| 1 psi (pound per square inch) | 51.7149 mmHg | 51.7149 |
| 1 torr | 1 mmHg | 1 |
Key Points:
- Standard atmospheric pressure: 760 mmHg (1 atm)
- 1 mmHg is approximately equal to 1 torr (slight difference at high precision)
- mmHg is commonly used in medical settings, especially for blood pressure measurements
Common Pressure Values:
| Condition | Pressure in mmHg |
|---|---|
| Normal atmospheric pressure at sea level | 760 mmHg |
| Normal blood pressure (systolic/diastolic) | 120/80 mmHg |
| High blood pressure threshold | 140/90 mmHg |
| Low blood pressure threshold | 90/60 mmHg |
| Typical tire pressure | 2068-2413 mmHg (40-47 psi) |
Conversion Formulas:
- To convert from any unit to mmHg, multiply by the conversion factor
- To convert from mmHg to another unit, divide by the conversion factor
Important Notes:
- The mmHg unit is non-SI but widely used in medicine and meteorology
- In clinical settings, blood pressure is often written as “120/80 mmHg” (systolic/diastolic)
- Pressure decreases with altitude at approximately 1 mmHg per 10 meters of elevation
- Mercury barometers are being phased out due to environmental concerns, but the mmHg unit remains in use
Applications:
- Medical: Blood pressure measurements
- Meteorology: Atmospheric pressure (though hPa or mbar are more common)
- Vacuum technology: Measuring low pressures
- Industrial processes: Various pressure measurements
Historical Context:
- The mmHg unit originated from the use of mercury barometers invented by Evangelista Torricelli in 1643
- The torr unit is named after Torricelli and is nearly equivalent to mmHg
Precision and Interchangeability:
- For most practical purposes, 1 mmHg = 1 torr
- The exact conversion is 1 torr = 133.322368 Pa, while 1 mmHg = 133.322387415 Pa
- This difference is negligible in most applications
Safety Considerations:
- Mercury is toxic; modern digital pressure gauges are preferred over mercury-based instruments
- Always specify the pressure unit to avoid confusion and potential safety issues
This table and additional information provide a comprehensive overview of pressure conversions related to mmHg, including key conversion factors, common values, and important considerations. This knowledge is crucial for medical professionals, scientists, engineers, and anyone working with pressure measurements in various fields.