内蒙古科技大学
本 科 毕 业 论 文
学生姓名:
学 号: 0809810026
专 业:铃木秀一 应用物理
指导教师:
电容液位
2012年5月9防伪胶带日
摘要
糖蜜酒精电容式物位计测量技术广泛应用于建筑、石油、化工、矿山、储运等工业生产领域,对于提高产品质量,优化过程控制具有十分重要的作用。本文就电容式物位计的几种常见的应用做出介绍。其中本文对射频导纳测量原理进行了详细论述及推导,给出了消除挂料影响、测量真实物位的方法。然后详细论述了射频导纳测量原理的电路实现,包括电源电路,复位电路,激励信号发生电路,信号检波电路,滤波电路以及信号采集电路。其次对电容式物位计如何克服杂散电容信号的影响自行葫芦
,得到准确的测量结果,是本文的研究重点。 本文在比较多种测量微小电容方法后选用充放电方法,基于充放电法,本文设计了两种电路,对两种电路的比较,选性能优者,并在信号传递过程中应用“驱动电缆法”开发出测量稳定,抗干扰能力强的电路方案。 关键词:电容式;物位计;射频导纳
ABSTRACT
Capacitive material level measurement technology are widely used in the construction, petroleum, chemical, mining, transportation and other areas of industrial production, to improve product quality, optimize process control plays a very important role. The capaciti
ve level gauge of several common used to make presentation. One of the radio frequency admittance measurement principle is discussed and derived, is given by the elimination of material hanging effect, measuring the true level method. Then in detail elaborated the principles of radio frequency admittance circuit, including a power supply circuit, reset circuit, an excitation signal generation circuit, a signal detection circuit, a filter circuit and a signal collecting circuit. The capacitive level gauge how to overcome the influence of the stray capacitance signal, to obtain accurate measurement results, is the focus of this article. Based on the comparison of several measurement of small capacitance method selection of charging and discharging method, based on the charging and discharging method, this paper designs two kinds of circuit, the two circuit compares the performance of the best, and, in the signal transmission process in the application of" method of driving cable" developed the measurement stability, strong anti-interference ability of the circuit scheme.
Keywords: Capacitor; level meter; radio frequency admittance
目录
前言 1
一 电容式物位计的基本原理 2
圣诞工艺品
二 电容式物位计的应用 4
2.1 射频导纳物位测量 4
2.1.1电容式液位计的测量转换电路 4
2.1.2 导电介质挂料对测量的影响 4
2.1.3 射频导纳物位测量仪的工作原理 5
2.1.4 测量系统的实现 6
2.2 HX型分段物位计的应用 7
2.2.1 分段电容式物位计检测方法简介 7
2.2.2 实检测方法的实现 8
2.3 电容式物位计在碱蒸发器上的应用 9
三 电容式物位计在应用中应注意的几个问题 9
3.1 选型 9
3.2 测量回路中接地点的处理 10
3.3 应用中常见的故障 11
3.4 标定方法 11
结束语 13