The electron multiplier converts incident ions into an amplified electric current used to record measurements of the ion signal in ICP-MS Systems.

As the voltage in the system increases the amplification factor (or gain) increases. In general the electron multiplier can measure a count of 1.6E10. The system should be replaced when the total ion count reaches more than 3.2E11 and the sensitivity is less than 4000 counts with 10 ppb Y (even when applying detector voltage above 2700 V).