Patent ID: 9324547
Filing Date: 2016-04-26
CPC Classification: H01J

Claim Text:
1. A method of mass analysis comprising: accumulating a first batch of ions in a mass analyser; detecting the first batch of ions accumulated in the mass analyser using image current detection to provide a first detected signal; determining a total charge or total ion content of the first batch of ions from the first detected signal; and accumulating a second batch of ions in the mass analyser; wherein the method comprises controlling the number of ions in the second batch of ions accumulated in the mass analyser using an algorithm based on the total charge or total ion content determined from the first detected signal; and wherein the method comprises, prior to accumulating the second batch of ions in the mass analyser, adjusting one or more parameters of the algorithm based on a measurement of ion current or charge, of ions that have not been injected into the mass analyser, the measurement obtained using an independent detector located outside of the mass analyser and based on other than image current detection.