磁悬浮分子泵用Hartley涡流传感器

工业领域的磁悬浮分子泵用位移传感器除了要具有良好的静态特性外,还应具有高动态响应特性,同时其体积大小还影响着磁悬浮分子泵的抽速、真空度和压缩比。针对高真空磁悬浮分子泵,提出了一种基于Hartley原理的电涡流位移传感器设计方法,将传感器对称探头接入同一振荡电路作为工作电感。对传感器的动态特性进行了分析,并提出了对其动态响应特性在不影响灵敏度和线性度等静态性能的情况下进行补偿的方法。实验结果表明,在-0.4~0.4mm内,传感器的线性度为±1.17%,灵敏度为9.901mV/μm,分辨率为0.25%,动态响应带宽达到了10.2kHz,两径向四路位移信号测量集成电路板体积仅为π×4~2 cm~2,大大减小了传感器体积,满足了磁悬浮分子泵面向更高抽速和更高真空度的发展需求。

Hartley eddy current sensor used in maglev molecular pump

For the displacement sensor used in maglev molecular pump in the industrial field, in addition to good static characteristic and high dynamic characteristic requirements, its volume also affects the pumping speed, the vacuum and the compression ratio of the maglev molecular pump. Aiming at the high-vacuum maglev molecular pump, a design method of the eddy current displacement sensor (ECDS) based on the Hartley oscillator was proposed. The symmetrical probes were connected into the same oscillation circuit as working inductors. Then the dynamic characteristic of the ECDS was analyzed in detail. And a method to compensate the response bandwidth without affecting the sensitivity and the linearity was put forward. Experimental results indicated that in the measurement range of -0.4-0.4 mm, the linearity came to ±1.17% and the sensitivity achieved 9.901 mV/μm, the resolution was ±0.25% and the response bandwidth was 10.2 kHz. The volume of the integrated circuit board of the two radial four-way displacement signal was only π×4² cm², which greatly reduced the sensor volume. It can satisfy the requirements of the maglev molecular pump for higher pumping speed and higher vacuum.