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Development of a laser vacuum gauge using a photothermal effect

利用光热效应开发激光真空计

基本信息

批准号：
01850082
负责人：
INABA Seiki
金额：
$ 1.73万
依托单位：
Gifu National College of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01850082/
关键词：
Photothermal effect Photoacoustic effect Laser Vacuum gauge

项目摘要

An Optical vacuum gauge is useful because of no electrodes inside vacuum systems. It is effective to measure the pressure for the space with very small amounts and to inspect the pressure of vacuum sealed devices. On the other hand, a photothermal effect is profitable for vibrating a membrane with no contact. In this investigation, the photothermal effect has been applied to the optical vacuum gauge. Following results have been obluained.1. It is cleared that the x)ressure in the low vacuum r-eyion (from 1 to 760 Torr) can be determined from the resonance frequency shift which depends on the 0'as density. Determinations by the resonance frequency is effective because of its accuracl and of its few affections from noises.2. Resonance frequency of the photothermal vibration shifted also in the medium vacuum rereion (from 1 to 10^<-3> Torr) since the temperature of the vibration, membrane increased with decreasing pressure. This is due to the pressure dependence of the thermal conductivity of ambient eases. It was cleared that the membrane having the larger thermal expdnsibn t coefficient showed the larver resonance frequency shift.3. Above methods are not effective for unknown composition eases. The rhotothermal vibration was applied to a diaphramm manometer, with which the space of unknown pressure and that of known pressure are divided. The resonance frequency shifts by the force caused from the differential pressure. The pressure from 10 to 10^<-3> torr could be determined.

光学真空计是有用的，因为真空系统内没有电极。对极少量的空间压力进行测量，对真空密封装置的压力进行检测是有效的。另一方面，光热效应对于振动无接触的膜是有利的。本研究将光热效应应用于光学真空计。结果如下：结果表明，低真空区域（1 ~ 760 Torr）的x)压力可以由共振频移确定，而共振频移取决于0′as密度。共振频率测定方法准确，且不受噪声影响，是一种有效的方法。光热振动的共振频率在介质真空条件下也发生了位移（从1到10^<-3> Torr），因为振动时膜的温度随压力的降低而升高。这是由于环境材料的热导率对压力的依赖性。结果表明，热膨胀系数较大的膜具有较大的共振频移。以上方法对未知的组合物不有效。将热激振动作用于膜片压力计，用该膜片压力计划分未知压力空间和已知压力空间。由压差引起的力使共振频率发生位移。可以确定10 ~ 10^<-3> torr的压力。