作者：陈超云, 王灿, 文慧卿
作者单位：上海市计量测试技术研究院，上海 201203
关键词：计量学;有限元仿真;磁感应强度;磁力悬浮;密度测量
摘要：
针对现有抗磁性材料密度测量的磁力悬浮装置存在灵敏度低、分辨率低的问题，提出一种沿着弱磁化方向测量抗磁性材料密度的方法，以减小测量范围的方式来提高装置的分辨率。使用有限元仿真软件在磁化方向θ=0°和90°时对不同磁体间距d进行参数化扫描，得到悬浮区间的磁感应强度分布。θ=0°时，呈现磁场梯度大、测量范围大、灵敏度低、分辨率低的特点；θ=90°时，呈现磁场梯度小、测量范围小、灵敏度高、分辨率高的特点。标准玻璃浮子悬浮实验表明：θ=0°时，由于缺乏足够的灵敏度来克服浮子之间的接触、排斥作用，浮子始终呈现聚集状态；θ=90°时，且磁体间距满足d=l（磁体长度）时，分辨率提高到δρmin=0.02 kg/m3。该装置结构简单，能够区分出材料微小密度差异，适用于低质量、小尺寸、不均匀、不规则抗磁性材料的密度测量，在密度计量领域具有一定的应用前景。
a high-resolution measurement method for the density of diamagnetic materials
chen chaoyun, wang can, wen huiqing
shanghai institute of measurement and testing technology, shanghai 201203, china
abstract: aiming at the problems of low sensitivity and low resolution of existing magnetic levitation device for measuring the density of diamagnetism materials, a method for measuring the density of diamagnetic materials along the direction of weak magnetization is proposed to improve the resolution of the device by reducing the measurement range. the finite element simulation software is used to perform parametric scanning of different magnet spacing d when the magnetization direction θ=0° and 90°, and the magnetic induction intensity distribution in the levitation zone is obtained. when θ=0°, it has the characteristics of large magnetic field gradient, large measurement range, low sensitivity, and low resolution; when θ=90°, it has the characteristics of small magnetic field gradient, small measurement range, high sensitivity and high resolution. the standard glass float suspension experiment shows that: when θ=0°, the floats are always aggregated due to the lack of sufficient sensitivity to overcome the contact and repulsion between the floats; when θ=90°, and the distance between the magnets satisfies d=l (magnet length), the resolution is increased to δρmin=0.02 kg/m3. the structure of the device is simple, and it can distinguish the small density difference of the material. it is especially suitable for the density measurement of low-quality, small-sized, uneven, and irregular diamagnetic materials, and has certain application prospects in the field of density measurement.
keywords: metrology;finite element simulation;magnetic induction;magnetic levitation;density measurement
2024, 50(7):186-190 收稿日期: 2023-05-31;收到修改稿日期: 2023-07-19
基金项目:
作者简介: 陈超云（1991-），男，浙江金华市人，工程师，硕士，研究方向为密度黏度计量。
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