General
Bar to PSIG Conversion Calculator
Convert pressure measurements between bar and PSIG (gauge pressure) quickly and accurately.
Enter a value to see the conversion result
Related to Bar to PSIG Conversion Calculator
The Bar to PSIG Conversion Calculator is designed to convert pressure measurements between bar and pounds per square inch gauge (PSIG). Unlike absolute pressure measurements (PSI), PSIG represents gauge pressure, which is the pressure relative to atmospheric pressure. This calculator uses precise conversion factors and automatically accounts for atmospheric pressure in the calculations.
Conversion Formulas
To convert from bar to PSIG:
PSIG = (bar × 14.5038) - 14.7
To convert from PSIG to bar:
bar = (PSIG + 14.7) ÷ 14.5038
The calculator uses the standard atmospheric pressure of 14.7 PSI and the conversion factor of 1 bar = 14.5038 PSI. These values ensure accurate conversions for industrial and engineering applications where gauge pressure measurements are required.
Gauge pressure (PSIG) is the pressure relative to the local atmospheric pressure. This makes it different from absolute pressure (PSI or PSIA) which is measured relative to a perfect vacuum. Understanding this difference is crucial for many industrial and engineering applications.
Key Characteristics of PSIG
• 0 PSIG equals atmospheric pressure (approximately 14.7 PSI at sea level)
• Negative PSIG values indicate pressure below atmospheric pressure
• Positive PSIG values indicate pressure above atmospheric pressure
• PSIG is commonly used in industrial pressure measurements
• Most pressure gauges display PSIG by default
Common Applications
• Tire pressure measurements
• Industrial process control
• Hydraulic and pneumatic systems
• HVAC systems
• Compressed air systems
1. What is the difference between PSI and PSIG?
PSI (pounds per square inch) typically refers to absolute pressure measured from a perfect vacuum, while PSIG (pounds per square inch gauge) measures pressure relative to atmospheric pressure. At sea level, PSIG is approximately 14.7 PSI less than PSI/PSIA.
2. Why is PSIG commonly used instead of absolute pressure?
PSIG is preferred in many practical applications because it directly shows the pressure difference from atmospheric pressure. This makes it more intuitive for applications like tire pressure, where we want to know how much additional pressure is being applied above atmospheric pressure.
3. How does altitude affect PSIG measurements?
PSIG measurements are relative to local atmospheric pressure, which changes with altitude. However, since PSIG is measured relative to whatever the local atmospheric pressure is, PSIG readings remain consistent regardless of altitude. This is one of the advantages of using gauge pressure.
4. Can PSIG be negative?
Yes, PSIG can be negative when the pressure is less than atmospheric pressure. For example, a vacuum pump might show negative PSIG values. The lowest possible PSIG value at sea level is approximately -14.7 PSIG, which represents a perfect vacuum.
5. What is the scientific source for this calculator?
This calculator uses conversion factors established by the National Institute of Standards and Technology (NIST) and follows the International System of Units (SI). The conversion between bar and PSI (1 bar = 14.5038 PSI) is derived from the fundamental definitions of these units, where 1 bar equals 100,000 Pascal. The atmospheric pressure value of 14.7 PSI is the standard value defined by the International Standard Atmosphere (ISA) at sea level conditions.