应用于条干均匀检测的长直圆柱面电容传感器

鉴于传统结构的电容传感器不能多径向测量圆形截面棉条的缺点，提出采用长直圆柱面式电容传感器对棉条的均匀度进行检测，从而得到更准确的数据。根据棉条的介电常数与传感器电容值之间的关系，推导出长直圆柱面电容传感器的数学模型，并分析了传感器的结构参数对传感器电容值变化的影响。采用一种新型的基于充放电原理的微电容测量电路，测量加入不同粗细的棉条时，传感器电容值对应的输出电压，验证了传感器的数学模型。

Cylinder Surface Capacitance Sensor Applied to Examine Yarn Irregularity

Considering the disadvantages of conventional capacitance sensor, a long cylindrical surface capacitance sensor of measuring the uniformity of yarn was presented. It is based on the relation between the yarn's and the sensor's capacitance, which gaves the mathematical model of long cylindrical capacitance sensor, analyses how the sensor's structures influence the changes of the capacitance. A new micro-capacitance circuit which was based on the transfer principle of charging and discharging shows the following features: while joining yarns of different thickness, the capacitance of sensor gives the corresponding output voltage, which validates the mathematical model of sensor and gains a much more exact result.