公开(公告)号：US3839655A

公开(公告)日：1974-10-01

申请号：US39139273

申请日：1973-08-24

Applicant: VARIAN ASSOCIATES

Inventor： HELGELAND W ,  SHELDON D

IPC: G01L21/32 ,  H01J41/04 ,  H01J41/14

CPC classification number: H01J41/04

Abstract: An improved Bayard-Alpert type vacuum ionization tube includes an electron collecting grid surrounding and coaxial with a centrally located positive ion collector. The grid has an inner diameter of approximately 0.5 inches and an electron emitting filament is positioned outside of the grid and spaced from the grid by approximately 0.2 inches. A grounded shield screen surrounds the grid outside of the filament and is coaxial with the collector. The tube has constant vacuum gauging sensitivity over the range from 10 1 to 5 X 10 10 torr.

Abstract translation: 改进的Bayard-Alpert型真空电离管包括围绕并与中心定位的正离子收集器同轴的电子收集栅。 栅格具有大约0.5英寸的内径，并且电子发射丝位于栅格的外部并与网格间隔约0.2英寸。 接地屏蔽屏幕围绕灯丝外部的栅格并与收集器同轴。 该管在10 -1至5×10 -10托的范围内具有恒定的真空计量灵敏度。

公开(公告)号：US3832642A

公开(公告)日：1974-08-27

申请号：US31047172

申请日：1972-11-29

Applicant: VARIAN ASSOCIATES

Inventor： HELGELAND W

IPC: G01R19/00 ,  H01J49/02 ,  H03F1/36

CPC classification number: G01R19/0023 ,  H01J49/022

Abstract: The current of a mass spectrometer collector is indicated by a circuit including an electrometer tube having a control grid connected to the collector. The electrometer tube is included in a d.c. amplifier having a negative feedback path including a very high valued resistor directly connected to the control electrode so that the collector current develops a sufficient voltage to be amplified to a detectable level by the amplifier. Automatic zero and reset control for the amplifier is provided by another d.c. negative feedback loop responsive to the amplifier output. The another negative feedback loop includes an operational amplifier integrator having an output connected to a screen grid of the electrometer tube. The operational amplifier integrator is selectively connected to the d.c. amplifier output so that when the mass spectrometer responds to a sample the integrator is not responsive to the d.c. amplifier output and the spectrometer current is indicated by a d.c. meter connected to the amplifier output via a variable gain operational amplifier.

Abstract translation: 质谱仪收集器的电流由包括具有连接到集电器的控制栅的静电计管的电路指示。 静电计管包含在直流电 放大器具有包括直接连接到控制电极的非常高值的电阻器的负反馈路径，使得集电极电流产生足够的电压，以由放大器放大到可检测的电平。 放大器的自动归零和复位控制由另一个直流电源提供。 响应于放大器输出的负反馈回路。 另一个负反馈回路包括运算放大器积分器，其具有连接到静电计管的屏栅的输出。 运算放大器积分器选择性地连接到直流电源。 放大器输出使得当质谱仪对样品做出响应时，积分器不响应直流。 放大器输出和光谱仪电流由直流电 仪表通过可变增益运算放大器连接到放大器输出。