Frequently Asked Questions
What are the benefits of a vacuum gauge?
The main benefit of a vacuum gauge is that it gives a clear indication of when then system has reached the desired vacuum levels so that the next process step can begin. The primary reason applications require vacuum is to create controlled environment. For example, in some instances you need to pull a vacuum to degas a system and remove impurities. Once you know that you are at an appropriate vacuum level then you can go ahead and proceed in a much cleaner process.
An additional benefit of using a vacuum gauge is the ability to identify system leaks by detecting elevated pressure. We can use these signs to narrow down what problems exist in the vacuum system and determine if they need to be replaced.
How does a vacuum gauge work?
Vacuum Gauges use either a direct or indirect method to determine the amount of gas molecules present in the measured area (or both as in the case with the HVG-2020B). The principle used to determine this measurement varies by the type of gauge. For example, a thermocouple gauge is a thermal conductivity gauge that indirectly measures gas molecules by using the heat transfer from the molecules and thermocouple wire to determine if vacuum is higher or lower. Whereas a direct gauge such as a piezo gauge measures pressure by directly interacting with the molecules.
Teledyne Hastings offers a Vacuum Gauge Glossary that explains the various vacuum gauges and their operating principles.
What’s the difference between a vacuum gauge and a pressure gauge?
A vacuum gauge is an absolute gauge that measures vacuum (negative pressure) with respect to absolute vacuum, i.e. a volume of space free of all gas molecules. A pressure gauge measures pressure with respect to the atmospheric pressure.
What is a Pirani Gauge?
A Pirani vacuum gauge is a type of thermal conductivity gauge that is also often referred to as a “thermal heat transfer gauge”. In a Pirani gauge, the rate of heat transfer is a function of the number of gas molecules present in the vacuum system. Pirani gauges are capable of providing reliable pressure measurement in a wide variety of vacuum technology applications. We have a blog that explains more in depth at this link.