Abstract
Metal valves available for ultra-high vacuum were produced according to the original design af Alpert and examined by a helium leak detector. Inverted type ionization gauges known as a Bayed-Alpert gauge were also made its characteristics were measured in detail. Using the above equipments an ultra-high vacuum apparatus was constructed. The vacuum of 10-10mmHg could be readily obtained by two or three hours baking and outgassing of ionization gauge. However, the highest vacuum achieved was not so good as reported by Alpert, because of the incomplete outgassing of the system.
