电渗模型电阻测量技术

Resistance Test Technology of Electroosmosis Model

本文对电渗模型中电阻测量方法进行了改良,提出串联法代替当前的电势测针法和夹具法,并提出适用于测量EKG电极电阻的走线法。串联不同长度的电渗土体测量电极与土体间的接触电阻,消除了电势测针法中测针与电极之间一段土体电阻值的误差影响,同时避免了电势测针插入土壤对土壤电流分布的影响;串联不同长度的电渗电极测量电极电阻率时,消除了夹具法测量时夹具和电极之间接触电阻的误差影响。结果表明:电势测针法所得的接触电阻与串联法得到的接触电阻的比值大多为1.3~1.4,验证了电势测针法将测针与电极间的一段土体值计入了接触电阻,造成测得的接触电阻偏大,故该比值的大小取决于该段土体的电阻值;串联法对于当前应用广泛的EKG电极并不适用,提出的走线法测量EKG电极电阻率能消除电极板内因嵌入铜制导线而电流分布不均的影响,测量结果基本不受电极长度的影响,具有良好的可靠性和稳定性,且测量便捷,方便应用于EKG电极生产工艺中,有比较广阔的应用前景;走线法测量EKG电极所得的电阻率与夹具法得到电阻率的比值大多为0.08~0.10,该比值主要与夹具和电极板间的接触电阻相关,该接触电阻仅取决于夹具和电极板,故可利用该比值对使用夹具法的测量结果进行修正;在许多室内试验和工程中均应用到了EKG电极,考虑EKG电极电阻率对整个试验和工程的能耗影响时,可参考电阻率比值0.08~0.10进行修正。

The resistance measurement methods in the electroosmotic model were modified.The series method was proposed to replace the current electric potential measurement and fixture method,and the wiring method suitable for measuring the resistance of EKG electrode was proposed.The method of measuring contact resistance between electrode and soil with electroosmotic soil of different lengths in series eliminated the error influence of resistance of a section of soil between the measuring needle and electrode in electric potential measurement and avoided the influence on current distribution because of inserting the potentiometric needle in the soil.The method of measuring electrode resistivity with electrodes of different lengths in series eliminated the error influence of contact resistance between electrode and fixture in fixture method.The experimental results showed that the ratio of contact resistance obtained by electric potential measurement to that obtained by series method was mostly between 1.3~1.4,which verified that the contact resistance measured by electric potential measurement was larger because resistance of a section of soil between the needle and electrode was included in the contact resistance.The ratio depended on the resistance value of the soil between the needle and electrode.Series method for EKG electrode was not applicable.The wiring method was presented to measure EKG electrode resistivity to eliminate the influence of uneven current distribution in the electrode plate due to embedded copper wire.The measurement results of wiring method were basically not affected by the length of the electrode,with good reliability and stability.The wiring method was convenient and applied in EKG electrode in the production process.There is a broad application prospect.The ratio of resistivity of EKG electrode obtained by wiring method to that obtained by the fixture method was mostly between 0.08~0.10.The ratio was mainly related to the contact resistance between electrode and fixture which just depended on the fixture and electrode.Therefore,the ratio could be used to modify previous results ob-tained by fixture method.The EKG electrodes have been used in many laboratory tests and projects.Considering the influence of the resistivity of EKG electrode on the energy consumption of the whole test and project,the resistivity ratio of 0.08~0.10 could be adopted for correction.