Stanford Research Systems www.thinksrs.com-IG1selectapp free download

File name www.thinksrs.com-IG1selectapp.pdf

www.thinkSRS.com 1 Select the Best Bayard-Alpert Ionization Gauge for Your Application An immense amount of research and development work, by many talented scientists and engineers, has led to a variety of new Bayard-Alpert Gauge (BAG) product designs. In fact, a high vacuum user looking for a new BAG might be surprised, and possibly overwhelmed, by the large number of new commercial options that have become available. Standardization of the BAG design has made it possible for generic ion gauge controllers, such as the IGC100, to control gauges from many different manufacturers. This application note provides an overview of the current state of BAG technology to help high vacuum users choose the best hot-cathode ion gauge for their application. In This Application Note BAG Designs 3 Glass Tubulated Gauges 3 Broad-Range Glass Tubulated Gauges 5 Nude Gauges 5 High-Accuracy Gauges 7 Tiny Gauges 9 (408)744-9040 Stanford Research Systems www.thinkSRS.com 2 Selecting a Bayard-Alpert Ionization Gauge Stanford Research Systems (408)744-9040 www.thinkSRS.com Selecting a Bayard-Alpert Ionization Gauge 3 BAG Designs This application note provides an overview of the current state of the BAG technology to help choose the best hot-cathode ion gauge for any application. For detailed information on the principle of operation of BAGs see the application note, 'Bayard-Alpert Ionization Gauges'. Glass Tubulated Gauges The glass tubulated BAG is the most commonly used gauge design in the world. Glass tubulated gauges are also the most inexpensive BAGs available. The tubulated gauge has its electrodes surrounded by a glass envelope with a side tube that attaches to the vacuum system. The most common construction materials for the glass envelope are Nonex (an inexpensive glass used in old vacuum tubes) and Pyrex. Most tubulated BAGs are connected to the vacuum system through an O-ring compression fitting. Pyrex is the material selected when the side tube must be glass- blown directly on to the vacuum system. Kovar alloy is the material of choice when metallic tubulation is required for the side port. The thermal expansion coefficient of Kovar matches that of Pyrex producing strong glass-to-metal transitions. Kovar tubulation is sometimes combined with compression fittings, but most often it is welded to Klein or ConFlat