摘要
磁悬浮转子真空计在高真空范围内具有优异的计量特性,但水蒸气等可凝性气体在测试过程中会在腔室或者转子表面发生显著的吸附或相变,这将引起压力测量值产生偏差,导致磁悬浮转子真空计切向动量传递系数的非线性变化。针对此问题,首先通过对固态冰抽气升华产生平衡稳定的水蒸气前级压力,然后通过绝热膨胀获得标准压力,并分别在常温(23℃)和高温(150℃)下测试了水蒸气分子在腔室表面的吸附、脱附曲线,计算得到相同压力下对应的吸附量、脱附量,最后对测量值和修正后标准压力之间的偏差进行了分析。测试结果表明:常温(23℃)下难以获得精确的标准压力,只能计算关闭阀门后水蒸气分子在腔室及其附属管道壁面的吸附量;高温(150℃)下,部分水蒸气分子会吸附在温度小于150℃的旁余管道壁面,造成测量压力略小于标准压力。
Spinning rotor gauge has excellent metrological characteristics in high vacuum.However,condensable gas,such as water vapor,is more likely to absorb or occur phase transition on the chamber or rotor surface.It would lead to the deviation of the measurand,what is more,the nonlinear change of the tangential momentum accommodation coefficient.Pointing at this problem,a balanced and stable pre-stage pressure of water vapor was generated by pumping and sublimating solid ice,and then the standard pressure was obtained by adiabatic expansion.The adsorption and desorption curves of water vapor molecules on the chamber surface were tested at room temperature(23℃)and high temperature(150℃),respectively.The corresponding adsorption and desorption amounts under the same pressure were calculated.Finally,the deviation between the measured value and the revised standard pressure was analyzed.The determination results show that it is challenging to obtain the accurate standard pressure at 23℃.Only the adsorption amount of water vapor molecules on the walls of chamber and its associated pipelines can be calculated after closing the valve.At 150℃,some water vapor molecules may adsorb on the walls of adjacent pipelines with temperature lower than 150℃,resulting in the measured pressure slightly lower than the standard pressure.
作者
宋云见
习振华
李博文
张虎忠
李刚
张开旭
李得天
SONG Yunjian;XI Zhenhua;LI Bowen;ZHANG Huzhong;LI Gang;ZHANG Kaixu;LI Detian(Science and Technology on Vacuum Technology and Physics Laboratory,Lanzhou Institute of Physics,Lanzhou 730000,China;School of Mechanical Engineering and Automation,Northeastern University,Shenyang 110819,China)
出处
《真空》
2025年第1期10-14,共5页
Vacuum
基金
国家重点研发计划资助(2023YFF0717202)。
关键词
磁悬浮转子真空计
静态膨胀法
水蒸气
吸附
spinning rotor gauge
static expansion method
water vapor
adsorption
