Semiautomatic Data-Collection Systems for Mass Spectrometers

Abstract
Two programmed digital data‐collection systems have been developed and used with static‐field mass spectrometers to improve the precision of isotopic analyses of solid samples and to reduce the time required for collection and reduction of data. A large high‐sensitivity spectrometer using ion pulse counting detection has been equipped with a programmer and multiscaler so that up to four masses can be sequentially scanned and the resulting counts stored in different groups of the core memory. The simpler scheme of adding a programmed integrating digital voltmeter to sample the detector output of an analytical spectrometer is used where high sensitivity is not required. Both instruments use voltage switching between masses and magnetic sweeping of the mass peaks. Mass programming is done simply, but precisely and directly, by the use of operational amplifier techniques in voltage supplies.