公开(公告)号：US4067225A

公开(公告)日：1978-01-10

申请号：US779748

申请日：1977-03-21

申请人： Richard A. Dorman ,  Curtis D. Kissinger ,  Lawrence J. Lagace, Jr.

发明人： Richard A. Dorman ,  Curtis D. Kissinger ,  Lawrence J. Lagace, Jr.

IPC分类号： G01B7/02 ,  G01B7/16 ,  G01H11/06 ,  G01M1/22 ,  G01B7/22 ,  G01H11/00

CPC分类号： G01B7/023 ,  G01B7/08 ,  G01H11/06

摘要： A new capacitance type non-contact displacement and/or vibration measurement instrument sensing head is described together with a novel method of maintaining calibration of the instrument using such sensing head. The invention takes the form of a central probe member having a first guard ring disposed in coaxial, electrically insulated relationship about the central probe member and driven at the same potential and frequency as the probe member. A secondary driven guard ring coaxially surrounds the first guard ring and is electrically isolated from it and is driven at the same alternating current frequency but at a higher voltage of the order of 1.5 to 1 times higher. The additional secondary guard ring, driven at a suitably boosted voltage level and the same frequency as the central probe member, serves to focus the otherwise divergent electric field, thus producing a very significant improvement in the output linearity when operated at relatively large displacements. Experiments have shown that a probe in accordance with the invention of 1 inch overall diameter can now be used to measure displacements up to approximately 1 inch, whereas previously a probe of the similar outside diameter could be used to measure displacements of only approximately 1/10 of an inch, unless some form of electronic linearization of its output was employed. With the improved sensing head assembly of this invention calibration of the instrument can be more easily maintained by simply removing the probe from a measurement position, applying a ground potential to the secondary guard ring and adjusting the output of the instrument to a fixed reference value to thereby recalibrate the instrument.

摘要翻译： 描述了新的电容型非接触位移和/或振动测量仪器感测头以及使用这种感测头维持仪器的校准的新颖方法。 本发明采用中心探针部件的形式，该中心探针部件具有围绕中心探针部件以同轴电绝缘的关系设置并以与探针部件相同的电位和频率被驱动的第一保护环。 二次驱动保护环同轴地围绕第一保护环并且与其电隔离并且以相同的交流频率驱动，但是在1.5至1倍的更高电压下被驱动。 以适当升高的电压电平驱动并且与中心探针构件的频率相同的辅助保护环用于聚焦另外发散的电场，从而在以较大的位移运行时产生非常显着的输出线性的改善。 实验已经表明，现在可以使用根据本发明的1英寸总直径的探针来测量高达约1英寸的位移，而先前，类似外径的探针可以用于仅测量约1/10的位移 一英寸，除非采用其输出的某种形式的电子线性化。 利用本发明的改进的感测头组件，可以通过简单地从测量位置移除探针，将接地电位施加到第二保护环并将仪器的输出调节到固定的参考值，从而可以更容易地维持仪器的校准 从而重新校准仪器。