If you are unfamiliar with the terminology commonly used when talking about gauges and pressure measurements, it can be a bit confusing. Two terms that are often used interchangeably are PSI (pounds per square inch) and PSIG (pounds per square inch gauge). Although these two terms may seem similar, they have some key differences in what they measure. In this blog post, we’ll explore exactly what those differences are and how to understand them as part of your next project. Read on to discover the answer to the question: “What’s the difference between PSI and PSIG?”
What is PSI?
- PSI, or “pounds per square inch”, is a unit of pressure measurement that is commonly used to measure the strength of tire pressure, as well as many other pressures.
- PSI measures the amount of force applied to an area that is one square inch in size—the higher the PSI, the greater the force. In terms of air pressure, PSI typically measures atmospheric pressure on earth, and correctly Gauging PSI can help prevent expensive damages such as tires exploding when driven too fast.
- PSI not only helps indicate the performance level of our tires but can also be used to understand how to skateboard bearings work and the amount of force needed to impact two surfaces. PSI is an incredibly useful tool for both everyday life and industrial production activities all around us.
What is PSIG?
PSIG (pounds per square inch gauge) is a unit of measure used to describe the pressure inside a system that is relative to atmospheric pressure. This type of measurement gives an accurate representation of the pressure being exerted, regardless of any changes in atmospheric conditions. PSIG also takes into account changes in temperature in order to provide an exact PSI reading at all times. PSIG is typically used in industries such as oil and gas, automotive, and aerospace engineering. PSIG ensures that a system is working properly and prevents costly damage due to high or low PSI levels.
Difference Between PSI and PSIG
PSI and PSIG are both units of measure commonly used in the fields of engineering, meteorology, and manufacturing.
- PSI stands for pounds per square inch while PSIG stands for pounds per square inch gauge.
- The primary difference between PSI and PSIG is that PSI measures absolute pressure while PSIG is measured relative to atmospheric pressure.
- PSI is typically used to measure the pressure within a closed environment such as a compressor system, while PSIG is typically used in much larger scales such as measuring ocean tidal movements or atmospheric conditions.
Knowing which measurement tool to use is important in understanding the differences between the two unit systems, and the application of each.
Conclusion
PSIG is a measure of the pressure above that exerted by the atmosphere, while PSI is a measure of gauge pressure or the pressure above the atmospheric. Most people use PSI when referring to tires since it more accurately reflects the amount of air pressure in the tire than PSIG. When shopping for a new car, be sure to ask about the difference between PSI and PSIG so you can be sure you’re getting what you’re looking for.
