DEVICE FOR CONTROLLING THE SLIT WIDTH OF ADJUSTABLE SLIT ELECTRODES IN MASS SPECTROMETERS

摘要

The slit width defined by a pair of slit electrodes in a mass spectrometer is controlled by means of a pair of hot wires, one being coupled to each slit electrode. Each wire extends about two spaced supporting elements and a tensile bar is used to couple a midpoint of each hot wire to its respective electrode. A temperature control arrangement is also used and includes a heating wire coupled to all supporting elements to maintain the temperature of the supporting elements constant as the current in the hot wires is changed to vary the slit width. This type of operation is provided by connecting both the hot wires and heating wire to an electrical regulating device that maintains the sum of the currents in these wires at a constant value.