Development of a Novel Data Acquisition System for Quadrupole Mass Spectrometer

The electron multiplier is currently the preferred detector solution for most quadrupole mass spectrometers. However, the detector outputs a weak current signal, which is prone to interference from noise signals during subsequent processing and acquisition, resulting in a decrease in the instrument's signal-tonoise ratio. Aiming at the issues of susceptibility to interference and low signal-to-noise ratio in traditional quadrupole mass spectrometer data acquisition systems, a novel data acquisition system has been developed. For analog mode, the traditional ADC scheme is replaced by the VFC (Voltage-Frequency Conversion) solution. For pulse mode, a novel pulse signal conditioning circuit is developed, which can convert the irregular current pulse signals output in pulse mode into voltage pulses with consistent amplitude and pulse width for convenient acquisition. Utilizing this system on our self-made ICP-MS prototype platform to test gradient concentration standard solutions containing 9Be, 59Co, 89Y, 115In, 140Ce, and 209Bi, the experimental results demonstrate that under the strong electromagnetic interference of the ICP source, the stability, accuracy, and other key indicators of the novel data acquisition system meet the instrument's requirements