Wide range vacuum gauges are measurement instruments that use a combination of technologies to cover from atmosphere to ultra-high vacuum. Examples of these technologies include a Pirani gauge, piezo sensors, or hot and cold cathodes. A wide range gauge would use 2-3 of these technologies that couldn’t be covered by just one of them alone.

As an example, Pirani vacuum gauges measure a low to medium range vacuum and can be paired with either a piezo gauge or an ionization gauge to measure either atmospheric pressure or ultra-high vacuum depending on the purpose of the wide range gauge. This helps provide a compact solution to your vacuum application by providing a single port pressure measurement that is directly integrated into your system. There is a huge variety of vacuum gauge technologies used and this page will focus on some of the common vacuum gauge technologies and their many novel features that are used in wide range vacuum gauges.​

Cold Cathode Gauge

Cold cathode vacuum gauges are an indirect vacuum gauge used to measure pressure in a vacuum system. The cold cathode gauge is a type of ionization gauge in which a crossed high voltage electric field and a magnetic field set up a discharge. The resulting positive ion current is proportional to the pressure in the vacuum system.

Cold cathode gauges are used to measure from high vacuum to ultra-high vacuum. This can be as low 1 X 10^-10

Torr. By pairing cold cathode vacuum gauges with a Pirani gauge, you have a wide range vacuum gauge that provides single port measurement from medium to ultra-high vacuum. This is especially helpful for applications which require minimal air contaminants. In some cases, a wide range vacuum gauge can be further expanded upon by adding a 3rd technology. This would provide a compact solution that measures this wide range from atmospheric pressure to ultra-high vacuum. While this would provide a single port pressure measurement solution, there are typically other vacuum gauges in the system to confirm the readings on the wide range vacuum gauge.​

Product Features

The HVG-2020 has many novel features to provide a superior user experience.​

Applications

A load-lock is a vacuum chamber used in the vacuum industry for loading materials from atmospheric pressure into the main vacuum processing chamber. This is standard practice in the semiconductor industry as they transfer semiconductor wafers into a vacuum chamber. This is crucial to prevent any particle contamination. Proper load lock operation requires an accurate measurement at ambient (atmospheric) pressure and at the transfer pressure in the mTorr range. Pressure measurement in between these regions is useful for comprehensive diagnostics but is not critical to the function of the load lock.​.

The best technique for measuring pressure in the load lock requires two sensor technologies, each designed for the specific needs of the two distinct functions of the load lock. The need for a wide range vacuum gauge that uses a combination of technologies provides an ideal, compact solution. In most cases having two separate gauges with their own vacuum ports, cables, and electronics is practically undesirable and a single port pressure measurement is preferred. Typically, a vacuum gauge would be placed on the main chamber and on the fore line between the high vacuum pump and the fore pump.

Teledyne Hastings has detailed the use of wide range vacuum gauges that uses dual sensor technology in our application note.​​