What is the difference between vacuum gauge and pressure gauge

Measuring the pressure in a given system, such as HVAC or refrigeration units, offers key insights into potential maintenance and repair issues and assists in maintaining efficiency. Vacuum gauges and pressure gauges are similar but distinct instruments that take measurements using different units and ranges.

Keep reading to learn more about the differences between these valuable tools. A vacuum gauge measures pressure in a vacuum. Petropedia explained that vacuum gauges are generally used in situations where the pressure in a given system is lower than the atmospheric pressure. It's worth noting that, while vacuum gauges generally provide results in terms of a negative number because the pressure in the system is below the ambient pressure, absolute pressure is still positive, as it is above the value or reading provided by an absolute vacuum.

Instead of using absolute pressure as a measurement, most vacuum gauges utilise relative pressure. Vacuum gauges are important tools in a number of commercial and industrial applications, including measuring pressure in heat pumps, air conditioning and refrigeration systems.

A vacuum gauge is always paired with a vacuum pump, which creates the vacuum to be measured by the gauge. Why do technicians and maintenance specialists use vacuum pumps on these heating and cooling machines? As they operate, these systems can be contaminated by air, nitrogen and water, The Refrigeration School explained.

These foreign substances can interfere with normal operations, making the units less efficient, requiring longer periods of operation and incurring a higher cost over time.

Contaminants can also harm the system, shortening their useful life and leading to a potentially significant investment for replacement. Similarly, a vacuum must be created when adding new refrigerant to a heating and cooling system. You are commenting using your Facebook account. Notify me of new comments via email. Notify me of new posts via email. Skip to content 1. Absolute Pressure : It is the zero reference to a perfect vacuum, which exists in the air free space of the universe.

Absolute pressure is the sum of gauge pressure and atmospheric pressure. Gauge Pressure: It is the pressure, zero referenced against ambient pressure. Atmospheric Pressure : It is the pressure exerted by the weight of the atmosphere. Vacuum Pressure : It is the pressure below atmospheric pressure is measured by vacuum gauges.

Like this: Like Loading Leave a Reply Cancel reply Enter your comment here Fill in your details below or click an icon to log in:. Email required Address never made public. Name required. Follow Following. Measuring Pressure and Vacuum. Pressure is measured in ways that reflect how the pressure measurement is being used and the location where the pressure is being measured. A variety of techniques and devices are used for the measurement of pressure and vacuum. These are devices generally referred to as either pressure gauges or vacuum gauges.

Pressure measurement is usually described in reference to atmospheric pressure, absolute pressure or gauge pressure. Atmospheric or barometric pressure is the pressure exerted by the weight of the atmosphere and varies by altitude, location and weather. A column of air one square inch in cross-section from sea level to the top of the atmosphere weighs about