AS9120B, ISO 9001:2015, and FAA AC 0056B ACCREDITED

How Does a Vacuum Pressure Gauge Work?

Vacuum gauges are instruments that measure pressure below atmospheric pressure. They find use in a multitude of industries, ensuring the proper functionality and reliability of a particular system or equipment. As such, this blog will cover vacuum gauges, their uses, and their function to better understand their importance.

Before we dive into the peculiarities of vacuum gauges, you must familiarize yourself with vacuum pressure. For further context, normal atmospheric pressure is typically set as zero, and vacuum pressure is provided as negative values. Atmospheric pressure is the standard pressure at sea level and is defined as 101.325 kPa. That being said, the most common unit of measurement used to express pressure is bar or psi. Keep in mind that vacuum pressure and absolute pressure (Pabs) are not the same.

A majority of pressure gauges utilize a bended tube called a Bourdon tube. This tube has the ability to deflect when placed under a pressure differential between the medium and the atmosphere. This deflection is converted into a needle position on the dial via a mechanism.

Most gauges are designed with a bottom connection or panel mount and are available with plastic casings or stainless steel. While plastic is cheaper and corrosion-resistant, it is far more sensitive to impact. Moreover, they can be designed as analog gauges like a Bourdon tube pressure gauge or digital pressure gauge.

Many industries use vacuum gauges, ranging from the automotive industry, food and beverage, and manufacturing to pharmaceutical, chemical, nautical, and more. They serve as integral pieces of equipment, allowing countless assemblies to work optimally. Additionally, vacuum gauges offer incredible accuracy. The accuracy they provide can be defined as the difference between the real value and the value that is displayed on the dial, typically expressed as a percentage of the span.

The EN 837 standard provides accuracy requirements for pressure gauges based on accuracy classes. An accuracy class of 2.5 indicates that the gauge may deviate up to 2.5% of the span from the real value. Though they provide a good degree of accuracy, temperature fluctuations or heavy vibrations can affect gauge performance. More than that, there is also room for human error, as the observer may also have an effect on the accuracy.

It is important to note that vacuum pressure gauges and absolute pressure gauges are not the same. In fact, normal vacuum pressure gauges measure against the atmospheric pressure while absolute pressure gauges measure with reference to the absolute zero point. For these gauges to gather quantifiable data, they contain a reference chamber with a near full vacuum.

Similar to other industrial instruments that are subjected to a diverse set of environments, pressure gauges should be routinely checked to ensure their optimal functionality. If you find yourself in need of replacement gauges, diaphragm pressure gauges, vacuum pumps, or other specialized tools for repair, rely on Procurement Domain. Procurement Domain provides vacuum pressure gauges for various military and civilian applications, those of which are subjected to rigorous quality assurance measures, tests, verifications, and assessments. 

At Procurement Domain, we make it a priority to only source top-quality parts and components for our customers. With this in mind, we operate with AS9120B, ISO 9001:2015, and FAA AC 00-56B accreditation, and we adhere to a strict NO CHINA SOURCING pledge, ensuring that all offerings come from leading global entities that we trust. Kickoff the purchasing process with a competitive quote which you can access via our Instant RFQ service. Once you have completed an RFQ form, within 15 minutes, a dedicated representative will reach out with a customized solution that meets your parts requirements. Alternatively, you can give us a call or email; we are available 24/7x365!


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