研究了碳纤维水泥石压敏传感器(CFCPS)的制备方法、测试方法以及信号采集系统的建立方法,并对所定型的一种CFCPS进行了性能测试。研究表明:调整水灰比、减水剂掺量、分散剂掺量,采用碳纤维和碳黑复掺,同时采取合适的搅拌工艺,可制得性能稳定的CFCPS;CFCPS的电极宜采用埋入式网状电极,电阻测试方法应采用四电极法;所建立的基于电压信号的采集系统具有电路简单、精度高、方便实用等特点,并可以实现实时在线、多通道采集;所定型的CFCPS的输入(应力或应变)与输出(电阻率变化率)关系式为:△ρ=0.912σ(或△ρ=0.015ε),其输入范围为0~10MPa(0~578με)、输出范围为0~8%、灵敏度约为0.912%/MPa(-0.016%/με)、线性度约为139/6、重复性约为4.49%、迟滞性约为5.28%、零点输出约为2.52%、时间零漂移约为8.469/6。
Preparation method, measuring method and design method of data acquisition system of carbon fiber cement paste piezoresistive sensors (CFCPS) were studied, and properties of a kind of standardized CFCPS were measured. The results show that CFCPS with steady performance can be made by adjusting water cement ratio and fractions of water reducing agent and dispersing agent, using mixed addition of carbon fiber and black carbon and adopting suitable mix technology. Embedded net electrode is suitable for CFCPS and measuring method of resistance should use the four-electrode measuring method. The designed data acquisition system based on voltage signal has many advantages such as simple circuit, high precision of data and good practicability, and can realize real-time, on-line and multichannel acquisition. The relationship between input and output of the standardized CFCPS is △ρ=-0. 912a (or Aρ=--0. 016ε ), their input range is 0-10MPa(or 0-578με), output range is 0-8%, sensitivity is 0. 912%/MPa(or-0. 016με), linearity is about 13%, repeatability is about 4. 49%, hysteresis is about 5.28%, zero-output is about 2.52% and time zero-drift is about 8.46%.