Abstract: Method and apparatus for precisely mixing gases in which solenoid valves sequentially feed separate gases to be mixed to a common pressure regulator and flowmeter.

Abstract: A device is disclosed for charging and/or reading a capacitor associated with an electrometer incorporated in a radiation dosimeter for the purpose of initializing or "zeroing", the dosimeter at the commencement of a radiation measurement cycle or reading it at any time thereafter. The dosimeter electrometer has a movable electrode the position of which is indicative of the charge remaining on the dosimeter capacitor and in turn the amount of radiation incident on the dosimeter since it was zeroed. The charging device also includes means for discharging, immediately upon conclusion of the dosimeter capacitor charging operation, stray capacitance inherent in the dosimeter by reason of its mechanical construction. The charge on the stray capacitance, if not discharged at the conclusion of the dosimeter capacitor charging operation, leaks off during the measurement cycle, introducing measurement errors.