Understanding vacuum pressure measurement

Posted by Vacuum Science World News on May 28, 2019 3:15:16 PM

When it comes to choosing a vacuum gauge, understanding the application and vacuum pressure measurement required is crucial to making the right choice.

But while pressure measurement plays an important role in all vacuum applications, there’s no universal vacuum gauge that will respond accurately throughout the range from atmospheric pressure to 10-12 mbar.


A guide on how to choose the right vacuum gauge

In addition, materials of construction, required method of vacuum measurement, environment and electronics can all dictate the type of vacuum gauge used; each of which has its own range of measurements.

Ask yourself what the desired pressure is range you want to measure, as different pressure ranges require the use of different gauges. Also consider the allowed measurement uncertainty / requested accuracy.

For example, “direct” gauges measure the force associated with pressure independently from the composition of the gas being measured, whereas “indirect” gauges are dependent on the gas species being measured.

The Pirani vacuum gauge was designed to measure different pressures in vacuum  systems. Learn the story behind it here:


Vacuum gauges can also be categorised into active or passive gauges. “Active” gauges incorporate the electronic sensor, which transforms the measure and into an electrical pressure signal with a compact electronic control and evaluation unit. They indicate the pressure measured either in the form of an analogue measurement signal or a numerical value through a standardised digital interface.

All of the above (and the various applications) can make the selection process more challenging.

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That said, while applications are varied, the basic parameters for choosing a gauge are very similar. Most will want the most accurate reading possible, so finding a gauge that covers the necessary ranges should always be the first consideration.

In our eBook, A simple guide to vacuum pressure measurement we cover everything you need to know in order to select the right vacuum gauge for your application. Including selection criteria, types of gauges and how to make the right choice.

In the eBook, we cover:

  • Selection criteria, such as
    • pressure range and required accuracy,
    • application conditions,
    • communication & control requirements,
    • or cost and serviceability
  • Different gauges types, including:
    • Direct gauges
      • Elastic element vacuum gauges, bourdon vacuum gauge, capsule vacuum gauge and capacitance diaphragm gauge (CDG)
    • Indirect gauges
      • Pirani gauge, hot cathode ionisation vacuum gauge and cold cathode ionisation gauges
    • Active vs. passive gauges

To find out more about vacuum pressure measurement and ensure you select the right gauge for your application, download our free eBook by clicking the button below.