Bayard Alpert – Brief History Of Gauge Style

Bayard Alpert gauges were designed to overcome the limitations of earlier triode gauges. The advancements improve the measurement abilities of the gauge, as well as providing improvements in several other areas. Read on to see why this type of gauge should always be a consideration.

A vacuum system is only able to achieve its desired pressure through careful measuring and monitoring of the pressures and gases within the system. The ion gauge designed by Bayard and Alpert in 1950 works by ionising the gas molecules within the gauge volume. The ions are then collected on a thin wire, known as the collector wire. The gauge is then able to measure the pressure by measuring the resulting current to the collector; and in doing so, determine the number of molecules present. This determination is what gives the indication of pressure within the system. The ion gauge was a necessary advancement in UHV measuring technology because of the limitations of the triode gauge. As the electrons in triode grids create low-energy photoelectron emitting x-rays, the gauge is unable to accurately measure pressure below 10-8 Torr. The resulting current from the photoelectrons leaving the collector is the cause of the low pressure limit in the triode gauge. The problem was overcome by Bayard and Alpert by reconfiguring the collector and the grid to lower the current from the x-ray effect. By achieving a lower current, they were able to increase the effective measuring range of the gauge and therefore improve its usability within high and ultra high pressure environments.

To experience the benefits of a Bayard Alpert gauge for yourself, purchase your products and components from the specialists at Arun Microelectronics Limited. We supply gaugeheads, replacement filaments and all the accessories you need at If you experience issues with your products, our team can always be reached through the contact page on the website.