Method and apparatus

Abstract

A method of reducing electrical measurement noise in a detection apparatus (e.g., an ion mobility spectrometer or a mass spectrometer) configured to detect the arrival of ions at a collector electrode 118. The detection apparatus comprises an air mover 122 (e.g., a fan, pump or blower) to provide a flow of air in the apparatus. The method comprises: operating the air mover at an operating level to provide the flow of air; reducing operation of the air mover for a quiet period; and operating the detection apparatus to allow ions to travel to be detected by the collector electrode during the quiet period. The collector electrode may be subject to variations in capacitance due to mechanical vibration. The air mover may be a source of mechanical vibration. Mechanical vibration of the collector electrode may be reduced during the quiet period. A detection apparatus is also claimed.

Images