| 主权项 |
1. A mass spectrometer comprising:
ion optics for receiving ionized sample material from an ion source and conveying at least some ions from the ionized sample material through the ion optics; a time-of-flight mass analyzer coupled to the ion optics for receiving at least some of the ions conveyed by the ion optics, the mass analyzer comprising a time-of-flight chamber, an ion pulsing system for periodically generating an electrical field to direct groups of the received ions into the time-of-flight chamber, and an ion detector arranged to receive ions that have travelled through the time-of-flight chamber for generating a signal indicative of the number of ions arriving at the ion detector as a function of time, the signal including information about mass spectra of the groups of ions produced by the pulsing system; a digitizing system for receiving and digitizing the signal from the ion detector and for providing extended dynamic range data during a target period, the digitizing system comprising; first and second analog-to-digital converters, the first analog-to-digital converter being configured to receive and digitize the signal from the ion detector during a first time window coinciding with a first portion of each mass spectrum, and characterized by a low full scale voltage range; the second analog-to-digital converter being configured to receive and digitize the signal from the ion detector during a second time window coinciding with a second portion of each mass spectrum, and characterized by a high full scale voltage range; wherein the first and second time windows are offset time-wise relative to one another and overlap one another during the target period, and wherein the first and second time windows are selectively adjustable by a user to adjust the time window overlap during the target period. |
